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 (
    919, 918, 924, 922, 921, 925, 525, 917, 
    916, 955, 942, 941, 446, 953, 952, 951, 
    949, 948, 947, 946, 945, 944, 982, 980, 
    979, 978, 981, 478, 977, 975, 974, 973, 
    972, 971, 970, 994, 996, 493, 985, 986, 
    988, 990, 991, 993, 1003, 1001, 1000, 
    508, 5727, 5729, 5730, 5731, 5732, 5733, 
    5734, 5735, 5736, 5739, 5741, 5742, 
    5743, 5744, 5745, 5746, 5747, 5748, 
    5749, 5750, 5752, 5753, 5754, 5755, 
    5756, 5757, 5758, 5759, 5760, 5761, 
    5762, 7004, 7005, 7006, 7007, 7008, 
    7009, 7010, 7011, 7012, 7013, 7014, 
    7015, 10284, 10285, 10286, 10287, 10288, 
    10289, 10290, 10291, 10292, 10293
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00271

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "182.06"
    },
    "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": 196,
            "rows_produced_per_join": 196,
            "filtered": "100.00",
            "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_products_categories`.`product_id` in (919,918,924,922,921,925,525,917,916,955,942,941,446,953,952,951,949,948,947,946,945,944,982,980,979,978,981,478,977,975,974,973,972,971,970,994,996,493,985,986,988,990,991,993,1003,1001,1000,508,5727,5729,5730,5731,5732,5733,5734,5735,5736,5739,5741,5742,5743,5744,5745,5746,5747,5748,5749,5750,5752,5753,5754,5755,5756,5757,5758,5759,5760,5761,5762,7004,7005,7006,7007,7008,7009,7010,7011,7012,7013,7014,7015,10284,10285,10286,10287,10288,10289,10290,10291,10292,10293))",
            "cost_info": {
              "read_cost": "93.86",
              "eval_cost": "19.60",
              "prefix_cost": "113.46",
              "data_read_per_join": "3K"
            },
            "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": 9,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "49.00",
              "eval_cost": "0.98",
              "prefix_cost": "182.06",
              "data_read_per_join": "30K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}