SELECT 
  cscart_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      cscart_products_categories.link_type = "M", 
      CONCAT(
        cscart_products_categories.category_id, 
        "M"
      ), 
      cscart_products_categories.category_id
    )
  ) AS category_ids 
FROM 
  cscart_products_categories 
  INNER JOIN cscart_categories ON cscart_categories.category_id = cscart_products_categories.category_id 
  AND cscart_categories.storefront_id IN (0, 1) 
  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') 
WHERE 
  cscart_products_categories.product_id IN (
    86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 
    97, 100, 101, 102, 103, 104, 105, 106, 
    107, 108, 109, 110, 111
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00150

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "31.34"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "0.69"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "ALL",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "rows_examined_per_scan": 84,
            "rows_produced_per_join": 3,
            "filtered": "4.00",
            "cost_info": {
              "read_cost": "19.53",
              "eval_cost": "0.67",
              "prefix_cost": "20.20",
              "data_read_per_join": "8K"
            },
            "used_columns": [
              "category_id",
              "storefront_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "((`atulecarter_atul_demo3`.`cscart_categories`.`storefront_id` in (0,1)) and ((`atulecarter_atul_demo3`.`cscart_categories`.`usergroup_ids` = '') or find_in_set(0,`atulecarter_atul_demo3`.`cscart_categories`.`usergroup_ids`) or find_in_set(1,`atulecarter_atul_demo3`.`cscart_categories`.`usergroup_ids`)) and (`atulecarter_atul_demo3`.`cscart_categories`.`status` in ('A','H')))"
          }
        },
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "atulecarter_atul_demo3.cscart_categories.category_id"
            ],
            "rows_examined_per_scan": 2,
            "rows_produced_per_join": 0,
            "filtered": "10.33",
            "index_condition": "(`atulecarter_atul_demo3`.`cscart_products_categories`.`product_id` in (86,87,88,89,90,91,92,93,94,95,96,97,100,101,102,103,104,105,106,107,108,109,110,111))",
            "cost_info": {
              "read_cost": "9.11",
              "eval_cost": "0.14",
              "prefix_cost": "30.65",
              "data_read_per_join": "11"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids
86 238M
87 246M
88 247M
89 247M
90 247M
91 227M
92 227M
93 248M
94 248M
95 248M
96 248M
97 242M
100 242M
101 238M
102 227M
103 242M
104 242M
105 238M
106 238M
107 227M
108 242M
109 227M
110 243M
111 243M