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 (
    7608, 7279, 7609, 7610, 7611, 7261, 7612, 
    7614, 7613, 7248, 7615, 7281, 7283, 
    7616, 7285, 7620, 7619, 7618, 7617, 
    7290, 7622, 7621, 7624, 7277, 7623, 
    7293, 7625, 5985, 8264, 8474, 8475, 
    2441, 2465, 8478, 2432, 8485, 8484, 
    8483, 2455, 8488, 8487, 8486, 8490, 
    8489, 2438, 2459, 8492, 8491, 8493, 
    1538, 8496, 1517, 8498, 8497, 1532, 
    8502, 8501, 8499, 1528, 8505, 8503, 
    4949, 8510, 8511, 8513, 8512, 10135, 
    10136, 10137, 10138
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00457

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "215.91"
    },
    "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": 248,
            "rows_produced_per_join": 248,
            "filtered": "100.00",
            "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_products_categories`.`product_id` in (7608,7279,7609,7610,7611,7261,7612,7614,7613,7248,7615,7281,7283,7616,7285,7620,7619,7618,7617,7290,7622,7621,7624,7277,7623,7293,7625,5985,8264,8474,8475,2441,2465,8478,2432,8485,8484,8483,2455,8488,8487,8486,8490,8489,2438,2459,8492,8491,8493,1538,8496,1517,8498,8497,1532,8502,8501,8499,1528,8505,8503,4949,8510,8511,8513,8512,10135,10136,10137,10138))",
            "cost_info": {
              "read_cost": "104.31",
              "eval_cost": "24.80",
              "prefix_cost": "129.11",
              "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": 12,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "62.00",
              "eval_cost": "1.24",
              "prefix_cost": "215.91",
              "data_read_per_join": "38K"
            },
            "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')))"
          }
        }
      ]
    }
  }
}