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 cscart_categories.category_id IN (168) 
  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 
  product asc, 
  products.product_id ASC 
LIMIT 
  0, 48

Query time 0.00129

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "11.67"
    },
    "ordering_operation": {
      "using_filesort": true,
      "grouping_operation": {
        "using_temporary_table": true,
        "using_filesort": false,
        "nested_loop": [
          {
            "table": {
              "table_name": "cscart_categories",
              "access_type": "const",
              "possible_keys": [
                "PRIMARY",
                "c_status",
                "p_category_id"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "category_id"
              ],
              "key_length": "3",
              "ref": [
                "const"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 1,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "0.00",
                "eval_cost": "0.20",
                "prefix_cost": "0.00",
                "data_read_per_join": "2K"
              },
              "used_columns": [
                "category_id",
                "storefront_id",
                "usergroup_ids",
                "status"
              ]
            }
          },
          {
            "table": {
              "table_name": "products_categories",
              "access_type": "ref",
              "possible_keys": [
                "PRIMARY",
                "pt"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "category_id"
              ],
              "key_length": "3",
              "ref": [
                "const"
              ],
              "rows_examined_per_scan": 5,
              "rows_produced_per_join": 5,
              "filtered": "100.00",
              "using_index": true,
              "cost_info": {
                "read_cost": "1.10",
                "eval_cost": "1.00",
                "prefix_cost": "2.10",
                "data_read_per_join": "80"
              },
              "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": 2,
              "filtered": "42.58",
              "cost_info": {
                "read_cost": "5.00",
                "eval_cost": "0.43",
                "prefix_cost": "8.10",
                "data_read_per_join": "10K"
              },
              "used_columns": [
                "product_id",
                "product_type",
                "status",
                "company_id",
                "usergroup_ids",
                "parent_product_id"
              ],
              "attached_condition": "((`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`.`company_id` in ('1','2','3','4','5','6')) and (`atulecarter_atul_demo1`.`products`.`product_type` <> 'D'))"
            }
          },
          {
            "table": {
              "table_name": "companies",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "company_id"
              ],
              "key_length": "4",
              "ref": [
                "atulecarter_atul_demo1.products.company_id"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 0,
              "filtered": "16.67",
              "cost_info": {
                "read_cost": "2.13",
                "eval_cost": "0.07",
                "prefix_cost": "10.65",
                "data_read_per_join": "2K"
              },
              "used_columns": [
                "company_id",
                "status",
                "company"
              ],
              "attached_condition": "(`atulecarter_atul_demo1`.`companies`.`status` = 'A')"
            }
          },
          {
            "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": "0.35",
                "eval_cost": "0.07",
                "prefix_cost": "11.08",
                "data_read_per_join": "1K"
              },
              "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": "0.38",
                "eval_cost": "0.21",
                "prefix_cost": "11.67",
                "data_read_per_join": "24"
              },
              "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 parent_product_id full_description
214 ASUS CP6130 CS-Cart P 0 <p>A glossy surface givess the CP6130 an air of elegance, while and an eye-catching power button inspired from the halo of a lunar eclipse seamlessly blends in to the front of the case.</p>
217 ASUS CP6230 CS-Cart P 0 <p>The ASUS CP6230 features a space-saving design with a hexagonal pattern lid that easily fits anywhere in your home. It draws you in with its elegant aesthetics but holds your attention with its computer power to tackle any task.</p>
218 ASUS Essentio CP1130 CS-Cart P 0 <p>The ASUS new Essentio CP1130 has sleek appearance and small size make it perfectly fit anywhere in your home. At the same time, it provides complete function and delivers ultimate performance for daily computing.</p>
244 Packard Bell OneTwo CS-Cart P 0 <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>