Sandbox

SELECT 
  SQL_CALC_FOUND_ROWS products.product_id, 
  descr1.product as product, 
  companies.company as company_name, 
  products.product_type, 
  products.parent_product_id, 
  descr1.full_description as full_description 
FROM 
  cscart_products as products 
  LEFT JOIN cscart_product_descriptions as descr1 ON descr1.product_id = products.product_id 
  AND descr1.lang_code = 'en' 
  LEFT JOIN cscart_product_prices as prices ON prices.product_id = products.product_id 
  AND prices.lower_limit = 1 
  LEFT JOIN cscart_companies AS companies ON companies.company_id = products.company_id 
  INNER JOIN cscart_products_categories as products_categories ON products_categories.product_id = products.product_id 
  INNER JOIN cscart_categories ON cscart_categories.category_id = products_categories.category_id 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  AND cscart_categories.storefront_id IN (0, 1) 
WHERE 
  1 
  AND companies.status IN ('A') 
  AND (
    products.usergroup_ids = '' 
    OR FIND_IN_SET(0, products.usergroup_ids) 
    OR FIND_IN_SET(1, products.usergroup_ids)
  ) 
  AND products.status IN ('A') 
  AND prices.usergroup_id IN (0, 0, 1) 
  AND products.parent_product_id = 0 
  AND products.company_id IN('1', '2', '3', '4', '5', '6') 
  AND products.product_type != 'D' 
GROUP BY 
  products.product_id 
ORDER BY 
  products.timestamp desc, 
  products.product_id ASC 
LIMIT 
  36, 12

Query time 0.00982

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "43.71"
    },
    "ordering_operation": {
      "using_filesort": true,
      "grouping_operation": {
        "using_temporary_table": true,
        "using_filesort": false,
        "nested_loop": [
          {
            "table": {
              "table_name": "companies",
              "access_type": "ALL",
              "possible_keys": [
                "PRIMARY"
              ],
              "rows_examined_per_scan": 6,
              "rows_produced_per_join": 1,
              "filtered": "16.67",
              "cost_info": {
                "read_cost": "3.27",
                "eval_cost": "0.20",
                "prefix_cost": "3.47",
                "data_read_per_join": "7K"
              },
              "used_columns": [
                "company_id",
                "status",
                "company"
              ],
              "attached_condition": "((`atulecarter_atul_demo1`.`companies`.`status` = 'A') and (`atulecarter_atul_demo1`.`companies`.`company_id` in ('1','2','3','4','5','6')))"
            }
          },
          {
            "table": {
              "table_name": "cscart_categories",
              "access_type": "ALL",
              "possible_keys": [
                "PRIMARY",
                "c_status",
                "p_category_id"
              ],
              "rows_examined_per_scan": 86,
              "rows_produced_per_join": 3,
              "filtered": "4.00",
              "using_join_buffer": "Block Nested Loop",
              "cost_info": {
                "read_cost": "20.01",
                "eval_cost": "0.69",
                "prefix_cost": "24.16",
                "data_read_per_join": "8K"
              },
              "used_columns": [
                "category_id",
                "storefront_id",
                "usergroup_ids",
                "status"
              ],
              "attached_condition": "(((`atulecarter_atul_demo1`.`cscart_categories`.`usergroup_ids` = '') or find_in_set(0,`atulecarter_atul_demo1`.`cscart_categories`.`usergroup_ids`) or find_in_set(1,`atulecarter_atul_demo1`.`cscart_categories`.`usergroup_ids`)) and (`atulecarter_atul_demo1`.`cscart_categories`.`status` in ('A','H')) and (`atulecarter_atul_demo1`.`cscart_categories`.`storefront_id` in (0,1)))"
            }
          },
          {
            "table": {
              "table_name": "products_categories",
              "access_type": "ref",
              "possible_keys": [
                "PRIMARY",
                "pt"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "category_id"
              ],
              "key_length": "3",
              "ref": [
                "atulecarter_atul_demo1.cscart_categories.category_id"
              ],
              "rows_examined_per_scan": 3,
              "rows_produced_per_join": 10,
              "filtered": "100.00",
              "using_index": true,
              "cost_info": {
                "read_cost": "3.63",
                "eval_cost": "2.06",
                "prefix_cost": "29.85",
                "data_read_per_join": "165"
              },
              "used_columns": [
                "product_id",
                "category_id"
              ]
            }
          },
          {
            "table": {
              "table_name": "products",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY",
                "status",
                "idx_parent_product_id"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "product_id"
              ],
              "key_length": "3",
              "ref": [
                "atulecarter_atul_demo1.products_categories.product_id"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 0,
              "filtered": "5.00",
              "cost_info": {
                "read_cost": "10.32",
                "eval_cost": "0.10",
                "prefix_cost": "42.24",
                "data_read_per_join": "2K"
              },
              "used_columns": [
                "product_id",
                "product_type",
                "status",
                "company_id",
                "timestamp",
                "usergroup_ids",
                "parent_product_id"
              ],
              "attached_condition": "((`atulecarter_atul_demo1`.`products`.`company_id` = `atulecarter_atul_demo1`.`companies`.`company_id`) and (`atulecarter_atul_demo1`.`products`.`parent_product_id` = 0) and ((`atulecarter_atul_demo1`.`products`.`usergroup_ids` = '') or find_in_set(0,`atulecarter_atul_demo1`.`products`.`usergroup_ids`) or find_in_set(1,`atulecarter_atul_demo1`.`products`.`usergroup_ids`)) and (`atulecarter_atul_demo1`.`products`.`status` = 'A') and (`atulecarter_atul_demo1`.`products`.`product_type` <> 'D'))"
            }
          },
          {
            "table": {
              "table_name": "descr1",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY",
                "product_id"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "product_id",
                "lang_code"
              ],
              "key_length": "9",
              "ref": [
                "atulecarter_atul_demo1.products_categories.product_id",
                "const"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 0,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "0.52",
                "eval_cost": "0.10",
                "prefix_cost": "42.86",
                "data_read_per_join": "2K"
              },
              "used_columns": [
                "product_id",
                "lang_code",
                "product",
                "full_description"
              ]
            }
          },
          {
            "table": {
              "table_name": "prices",
              "access_type": "ref",
              "possible_keys": [
                "usergroup",
                "product_id",
                "lower_limit",
                "usergroup_id"
              ],
              "key": "usergroup",
              "used_key_parts": [
                "product_id"
              ],
              "key_length": "3",
              "ref": [
                "atulecarter_atul_demo1.products_categories.product_id"
              ],
              "rows_examined_per_scan": 3,
              "rows_produced_per_join": 1,
              "filtered": "97.36",
              "using_index": true,
              "cost_info": {
                "read_cost": "0.55",
                "eval_cost": "0.30",
                "prefix_cost": "43.71",
                "data_read_per_join": "36"
              },
              "used_columns": [
                "product_id",
                "lower_limit",
                "usergroup_id"
              ],
              "attached_condition": "((`atulecarter_atul_demo1`.`prices`.`lower_limit` = 1) and (`atulecarter_atul_demo1`.`prices`.`usergroup_id` in (0,0,1)))"
            }
          }
        ]
      }
    }
  }
}

Result

product_id	product	company_name	product_type	full_description
287	Trefoil Hoodie	CS-Cart	P	<p>The adidas Originals Trefoil Hoodie has been a streetwear essential for decades, with its characteristic big hood, kangaroo pocket and large Trefoil. Now it's your turn to join the Trefoil men's hoodie crew and carry the legend forward.</p>
278	T-shirt, Color: White	CS-Cart	P
280	T-shirt, Color: Black	CS-Cart	P
282	T-shirt, Color: Blue	CS-Cart	P
247	Nokia N1 Pad 7.9" Quad-Core 64bit 2.3GHz 2GB 32GB Android 5.0	CS-Cart	P	<p>Nokia N1 smartphone with 7.90-inch 2048x1536 display powered by 2.3GHz processor alongside 2GB RAM and 8-megapixel rear camera.</p>
248	X-Box One	CS-Cart	P	<p>Xbox One's exterior casing consists of a two-tone "liquid black" finish; with half finished in a matte grey, and the other in a glossier black. The design was intended to evoke a more entertainment-oriented and simplified look than previous iterations of the console; among other changes.</p><div>It is powered by an AMD "Jaguar" Accelerated Processing Unit (APU) with two quad-core modules totaling eight x86-64 cores clocked at 1.75 GHz, and 8 GB of DDR3 RAM with a memory bandwidth of 68.3 GB/s. The memory subsystem also features an additional 32 MB of "embedded static" RAM, or ESRAM, with a memory bandwidth of 109 GB/s.</div>
241	Apple® - iPad® with Retina® display Wi-Fi - 32GB - White	CS-Cart	P	<p> iPad features a stunning Retina display, iSight® and FaceTime cameras, the all new A6X chip and ultrafast wireless. And with access to over 275,000 apps1 on the App Store, you can do more than ever. </p>
244	Packard Bell OneTwo	CS-Cart	P	<p> Great Packard Bell all in one PC with 23" HD LCD Multi Touchscreen and Windows 7. The PC is in perfect working order. The LCD screen is very crisp and bright and the touchscreen is responsive and easy to use The casing is in good but used condition, there is hardly a mark on it and only noticeable very close up. Comes with an Intel i3 CPU and a dedicated nVidia Geforce 315 video card for superb performance. Also has a Freeview TV card so you can watch and record TV.It has an HDMI out port making it simple to connect to a larger TV if required. It has had a fresh install of Windows 7 including the full Packard Bell software suite. Windows has been fully updated and you are ready to go straight out of the box. Has an active recovery partition enabling you to perform a full reset to factory defaults straight from the hard drive and also create a spare set of recovery discs. </p>
245	Apple - iPhone 5c 32GB Cell Phone - Green	CS-Cart	P	<p> A6 chip. 8MP iSight camera. 4-inch Retina display. Ultrafast LTE wireless. iPhone 5c has the things that made iPhone 5 an amazing phone — and more, including iOS 7. All in a completely new design that feels great in your hand. </p>
246	GoPro - Hero3+ Black Edition Camera	CS-Cart	P	<p> Take smooth video with up to 4K resolution with this GoPro Hero3+ Black Edition CHDHX-302 camera that features a waterproof housing and a wearable, mountable design that lets you easily film yourself engaging in your favorite activities. </p>
240	Apple® - iPad® with Retina® display Wi-Fi - 64GB - Black	CS-Cart	P	<p> iPad features a stunning Retina display, iSight® and FaceTime cameras, the all new A6X chip and ultrafast wireless. And with access to over 275,000 apps1 on the App Store, you can do more than ever. </p>
6	Toshiba 32C120U 32" Class 720P HD LCD TV	CS-Cart	P	<p>Think you need to break your budget to enjoy blockbuster HD entertainment? Not with Toshiba's 32" class C110U LCD HDTV. Featuring all-new design, this value-packed television looks great and works well in a living room, kitchen or bedroom. Increase detail and depth of the images on your screen with our impressive Dynalight technology.</p>