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, 835, 
    834, 841, 840, 839, 838, 837, 846, 845, 
    844, 843, 842, 851, 850, 849, 848, 847, 
    858, 857, 856, 855, 854, 863, 862, 861, 
    860, 859, 872, 871, 870, 869, 868
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00180

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "109.64"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "5.55"
      },
      "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": 5,
            "filtered": "9.25",
            "index_condition": "(`cscart`.`cscart_products_categories`.`product_id` in (592,593,831,830,829,828,827,835,834,841,840,839,838,837,846,845,844,843,842,851,850,849,848,847,858,857,856,855,854,863,862,861,860,859,872,871,870,869,868))",
            "cost_info": {
              "read_cost": "61.60",
              "eval_cost": "1.11",
              "prefix_cost": "104.09",
              "data_read_per_join": "88"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids
592 301M,366,374
593 374,301M,366
827 302,301,367M
828 302,301,367M
829 302,301,367M
830 367M,302,301
831 367M,302,301
834 301,372,373M
835 301,372,373M
837 301,368M,302
838 302,301,368M
839 302,301,368M
840 368M,302,301
841 301,368M,302
842 301,368M,302
843 301,368M,302
844 301,368M,302
845 302,301,368M
846 368M,302,301
847 368M,302,301
848 301,368M,302
849 301,368M,302
850 301,368M,302
851 302,301,368M
854 369M,302,301
855 369M,302,301
856 301,369M,302
857 301,369M,302
858 301,369M,302
859 302,301,369M
860 302,301,369M
861 369M,302,301
862 301,369M,302
863 301,369M,302
868 301,369M,302
869 301,369M,302
870 302,301,369M
871 369M,302,301
872 369M,302,301