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 (
    572, 571, 570, 569, 568, 678, 679, 680, 
    833, 832, 841, 840, 839, 838, 837, 853, 
    852, 863, 862, 861, 860, 859, 867, 866, 
    865, 864, 872, 871, 870, 869, 868, 874, 
    873, 878, 877, 876, 875
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00162

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "109.01"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "4.92"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "ALL",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "rows_examined_per_scan": 125,
            "rows_produced_per_join": 5,
            "filtered": "4.00",
            "cost_info": {
              "read_cost": "29.49",
              "eval_cost": "1.00",
              "prefix_cost": "30.49",
              "data_read_per_join": "20K"
            },
            "used_columns": [
              "category_id",
              "storefront_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "((`cscart`.`cscart_categories`.`storefront_id` in (0,1)) and ((`cscart`.`cscart_categories`.`usergroup_ids` = '') or find_in_set(0,`cscart`.`cscart_categories`.`usergroup_ids`) or find_in_set(1,`cscart`.`cscart_categories`.`usergroup_ids`)) and (`cscart`.`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": [
              "cscart.cscart_categories.category_id"
            ],
            "rows_examined_per_scan": 12,
            "rows_produced_per_join": 4,
            "filtered": "8.20",
            "index_condition": "(`cscart`.`cscart_products_categories`.`product_id` in (572,571,570,569,568,678,679,680,833,832,841,840,839,838,837,853,852,863,862,861,860,859,867,866,865,864,872,871,870,869,868,874,873,878,877,876,875))",
            "cost_info": {
              "read_cost": "61.60",
              "eval_cost": "0.98",
              "prefix_cost": "104.09",
              "data_read_per_join": "78"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids
568 300M,388
569 300M,388
570 388,300M
571 388,300M
572 300M,388
678 317,303M,315
679 303M,315,317
680 303M,315,317
832 301,374M,366
833 366,301,374M
837 368M,301,302
838 368M,301,302
839 302,368M,301
840 302,368M,301
841 301,302,368M
852 301,302,369M
853 369M,301,302
859 369M,301,302
860 369M,301,302
861 302,369M,301
862 301,302,369M
863 301,302,369M
864 369M,301,302
865 369M,301,302
866 369M,301,302
867 302,369M,301
868 301,302,369M
869 301,302,369M
870 369M,301,302
871 369M,301,302
872 369M,301,302
873 302,370M,301
874 302,370M,301
875 301,302,369M
876 301,302,369M
877 301,302,369M
878 301,302,369M