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 (
    278, 
    280, 
    282, 
    247, 
    248, 
    241, 
    244, 
    245, 
    246, 
    240, 
    6, 
    66, 
    166, 
    214, 
    219, 
    221, 
    223, 
    192, 
    194, 
    195, 
    196, 
    197, 
    198, 
    199, 
    200, 
    201, 
    202, 
    203, 
    204, 
    205, 
    206, 
    207, 
    208, 
    209, 
    210, 
    211, 
    212, 
    213, 
    215, 
    217, 
    218, 
    220, 
    222, 
    224, 
    225, 
    226, 
    227, 
    228, 
    229, 
    230, 
    231, 
    232, 
    233, 
    234, 
    235, 
    236, 
    237, 
    238, 
    239, 
    242, 
    243, 
    78, 
    79, 
    80, 
    81, 
    82, 
    83, 
    84, 
    85, 
    86, 
    87, 
    88, 
    89, 
    90, 
    91, 
    92, 
    93, 
    94, 
    95, 
    96, 
    97, 
    100, 
    101, 
    102, 
    103, 
    104, 
    105, 
    106, 
    107, 
    108, 
    109, 
    110, 
    111, 
    112, 
    113, 
    114, 
    115, 
    116, 
    117, 
    118, 
    119, 
    120, 
    121, 
    122, 
    123, 
    124, 
    125, 
    126, 
    127, 
    128, 
    129, 
    130, 
    131, 
    132, 
    133, 
    134, 
    135, 
    136, 
    137, 
    138, 
    139, 
    140, 
    141, 
    142, 
    143, 
    144, 
    145, 
    146
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00158

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "34.47"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "3.58"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "ALL",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "rows_examined_per_scan": 85,
            "rows_produced_per_join": 3,
            "filtered": "4.00",
            "cost_info": {
              "read_cost": "19.74",
              "eval_cost": "0.68",
              "prefix_cost": "20.42",
              "data_read_per_join": "11K"
            },
            "used_columns": [
              "category_id",
              "storefront_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "((`pankajecarter_systemsix`.`cscart_categories`.`storefront_id` in (0,1)) and ((`pankajecarter_systemsix`.`cscart_categories`.`usergroup_ids` = '') or find_in_set(0,`pankajecarter_systemsix`.`cscart_categories`.`usergroup_ids`) or find_in_set(1,`pankajecarter_systemsix`.`cscart_categories`.`usergroup_ids`)) and (`pankajecarter_systemsix`.`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": [
              "pankajecarter_systemsix.cscart_categories.category_id"
            ],
            "rows_examined_per_scan": 2,
            "rows_produced_per_join": 3,
            "filtered": "52.61",
            "index_condition": "(`pankajecarter_systemsix`.`cscart_products_categories`.`product_id` in (278,280,282,247,248,241,244,245,246,240,6,66,166,214,219,221,223,192,194,195,196,197,198,199,200,201,202,203,204,205,206,207,208,209,210,211,212,213,215,217,218,220,222,224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,242,243,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146))",
            "cost_info": {
              "read_cost": "9.11",
              "eval_cost": "0.72",
              "prefix_cost": "30.89",
              "data_read_per_join": "57"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        }
      ]
    }
  }
}