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 (
    11088, 11089, 11087, 11109, 11108, 11110, 
    11111, 11125, 11124, 11123, 11263, 
    11265, 11336, 11339, 11340, 11343, 
    11345, 11346, 11366, 11367, 11370, 
    11371, 11394, 11395, 11396, 11397, 
    11398, 11406, 11407, 11418, 11419, 
    11420, 11421, 11422, 11423, 11424, 
    11425, 11434, 11435, 11436, 11469, 
    11470, 11471, 11487, 11488, 11489, 
    11490, 11491, 11492, 11493, 11494, 
    11495, 11505, 11506, 11507, 11592, 
    11593, 11594
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00249

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "361.71"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 434,
            "rows_produced_per_join": 434,
            "filtered": "100.00",
            "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_products_categories`.`product_id` in (11088,11089,11087,11109,11108,11110,11111,11125,11124,11123,11263,11265,11336,11339,11340,11343,11345,11346,11366,11367,11370,11371,11394,11395,11396,11397,11398,11406,11407,11418,11419,11420,11421,11422,11423,11424,11425,11434,11435,11436,11469,11470,11471,11487,11488,11489,11490,11491,11492,11493,11494,11495,11505,11506,11507,11592,11593,11594))",
            "cost_info": {
              "read_cost": "166.41",
              "eval_cost": "43.40",
              "prefix_cost": "209.81",
              "data_read_per_join": "6K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "softwarepirmam_hewadelivard_cscart_4.cscart_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 21,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "108.50",
              "eval_cost": "2.17",
              "prefix_cost": "361.71",
              "data_read_per_join": "67K"
            },
            "used_columns": [
              "category_id",
              "storefront_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "((`softwarepirmam_hewadelivard_cscart_4`.`cscart_categories`.`storefront_id` in (0,1)) and ((`softwarepirmam_hewadelivard_cscart_4`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`softwarepirmam_hewadelivard_cscart_4`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`softwarepirmam_hewadelivard_cscart_4`.`cscart_categories`.`usergroup_ids`))) and (`softwarepirmam_hewadelivard_cscart_4`.`cscart_categories`.`status` in ('A','H')))"
          }
        }
      ]
    }
  }
}