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, 578, 579, 580, 
    581, 582, 678, 679, 680, 833, 832, 841, 
    840, 839, 838, 837, 853, 852, 867, 866, 
    865, 864, 872, 871, 870, 869, 868, 874, 
    873, 878, 877, 876, 875
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00110

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 (572,571,570,569,568,578,579,580,581,582,678,679,680,833,832,841,840,839,838,837,853,852,867,866,865,864,872,871,870,869,868,874,873,878,877,876,875))",
            "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
569 388,300M
570 388,300M
571 388,300M
572 300M,388
578 403,300M,389
579 403,300M,389
580 389,403,300M
581 389,403,300M
582 389,403,300M
678 315,317,303M
679 303M,315,317
680 303M,315,317
832 366,374M,301
833 374M,301,366
837 301,368M,302
838 301,368M,302
839 302,301,368M
840 302,301,368M
841 368M,302,301
852 301,369M,302
853 301,369M,302
864 301,369M,302
865 301,369M,302
866 302,301,369M
867 302,301,369M
868 301,369M,302
869 301,369M,302
870 301,369M,302
871 301,369M,302
872 302,301,369M
873 302,370M,301
874 302,370M,301
875 301,302,369M
876 369M,301,302
877 369M,301,302
878 302,369M,301