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 0.00111

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