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 (
    592, 593, 831, 830, 829, 828, 827, 833, 
    832, 835, 834, 841, 840, 839, 838, 837, 
    846, 845, 844, 843, 842, 851, 850, 849, 
    848, 847, 853, 852, 858, 857, 856, 855, 
    854, 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 0.00123

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "111.59"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "7.50"
      },
      "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": 7,
            "filtered": "12.50",
            "index_condition": "(`cscart`.`cscart_products_categories`.`product_id` in (592,593,831,830,829,828,827,833,832,835,834,841,840,839,838,837,846,845,844,843,842,851,850,849,848,847,853,852,858,857,856,855,854,863,862,861,860,859,867,866,865,864,872,871,870,869,868,874,873,878,877,876,875))",
            "cost_info": {
              "read_cost": "61.60",
              "eval_cost": "1.50",
              "prefix_cost": "104.09",
              "data_read_per_join": "120"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids
592 366,301M,374
593 374,366,301M
827 367M,302,301
828 302,301,367M
829 302,301,367M
830 302,301,367M
831 302,301,367M
832 374M,366,301
833 374M,366,301
834 301,372,373M
835 301,372,373M
837 301,368M,302
838 301,368M,302
839 302,301,368M
840 368M,302,301
841 368M,302,301
842 301,368M,302
843 301,368M,302
844 301,368M,302
845 301,368M,302
846 368M,302,301
847 368M,302,301
848 301,368M,302
849 301,368M,302
850 301,368M,302
851 301,368M,302
852 369M,302,301
853 369M,302,301
854 301,369M,302
855 301,369M,302
856 301,369M,302
857 301,369M,302
858 301,369M,302
859 369M,302,301
860 369M,302,301
861 301,369M,302
862 301,369M,302
863 301,369M,302
864 301,369M,302
865 369M,302,301
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 369M,302,301
873 302,370M,301
874 370M,301,302
875 301,369M,302
876 301,369M,302
877 301,369M,302
878 302,301,369M