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 (
    12259, 12260, 12261, 12262, 12263, 12264, 
    12265, 12266, 12267, 12268, 12269, 
    12270, 12271, 12272, 12273, 12274, 
    12275, 12276, 12277, 12278, 12279, 
    12280, 12281, 12282, 12283, 12284, 
    12285, 12286, 12287, 12288, 12289, 
    12290, 12291, 12292, 12293, 12294, 
    12295, 12296, 12297, 12298, 12299, 
    12300, 12301, 12302, 12303, 12304, 
    12305, 12306, 12307, 12308, 12309, 
    12310, 12311, 12312, 12313, 12314, 
    12315, 12316, 12317, 12318, 12319, 
    12320, 12321, 12322, 12323, 12324, 
    12325, 12326, 12327, 12328, 12329, 
    12330, 12331, 12332, 12333, 12334, 
    12335, 12336, 12337, 12338, 12339, 
    12340, 12341, 12342, 12343, 12344, 
    12345, 12346, 12347, 12348
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00266

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "60.67"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "1.89"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "ALL",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "rows_examined_per_scan": 46,
            "rows_produced_per_join": 1,
            "filtered": "4.00",
            "cost_info": {
              "read_cost": "5.15",
              "eval_cost": "0.18",
              "prefix_cost": "5.33",
              "data_read_per_join": "7K"
            },
            "used_columns": [
              "category_id",
              "storefront_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "((`test2_gaseus`.`cscart_categories`.`storefront_id` in (0,1)) and ((`test2_gaseus`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`test2_gaseus`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`test2_gaseus`.`cscart_categories`.`usergroup_ids`))) and (`test2_gaseus`.`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": [
              "test2_gaseus.cscart_categories.category_id"
            ],
            "rows_examined_per_scan": 83,
            "rows_produced_per_join": 1,
            "filtered": "1.24",
            "index_condition": "(`test2_gaseus`.`cscart_products_categories`.`product_id` in (12259,12260,12261,12262,12263,12264,12265,12266,12267,12268,12269,12270,12271,12272,12273,12274,12275,12276,12277,12278,12279,12280,12281,12282,12283,12284,12285,12286,12287,12288,12289,12290,12291,12292,12293,12294,12295,12296,12297,12298,12299,12300,12301,12302,12303,12304,12305,12306,12307,12308,12309,12310,12311,12312,12313,12314,12315,12316,12317,12318,12319,12320,12321,12322,12323,12324,12325,12326,12327,12328,12329,12330,12331,12332,12333,12334,12335,12336,12337,12338,12339,12340,12341,12342,12343,12344,12345,12346,12347,12348))",
            "cost_info": {
              "read_cost": "38.18",
              "eval_cost": "0.19",
              "prefix_cost": "58.78",
              "data_read_per_join": "30"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        }
      ]
    }
  }
}