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.company_id = 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 (
    1930, 795, 1158, 1221, 336, 571, 1147, 
    1307, 1450, 1676, 1768, 1945
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00131

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "139.23"
    },
    "grouping_operation": {
      "using_temporary_table": true,
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "0.81"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "ALL",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "rows_examined_per_scan": 115,
            "rows_produced_per_join": 2,
            "filtered": "2.00",
            "cost_info": {
              "read_cost": "27.56",
              "eval_cost": "0.46",
              "prefix_cost": "28.02",
              "data_read_per_join": "6K"
            },
            "used_columns": [
              "category_id",
              "company_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "((`eshopuga_upgr_4122`.`cscart_categories`.`company_id` = 1) and ((`eshopuga_upgr_4122`.`cscart_categories`.`usergroup_ids` = '') or find_in_set(0,`eshopuga_upgr_4122`.`cscart_categories`.`usergroup_ids`) or find_in_set(1,`eshopuga_upgr_4122`.`cscart_categories`.`usergroup_ids`)) and (`eshopuga_upgr_4122`.`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": [
              "eshopuga_upgr_4122.cscart_categories.category_id"
            ],
            "rows_examined_per_scan": 40,
            "rows_produced_per_join": 0,
            "filtered": "0.88",
            "index_condition": "(`eshopuga_upgr_4122`.`cscart_products_categories`.`product_id` in (1930,795,1158,1221,336,571,1147,1307,1450,1676,1768,1945))",
            "cost_info": {
              "read_cost": "92.00",
              "eval_cost": "0.16",
              "prefix_cost": "138.42",
              "data_read_per_join": "12"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        }
      ]
    }
  }
}

Result

product_id category_ids
336 435M
571 413M
795 427M,432
1147 398M
1158 401M
1221 397M
1307 398M
1450 432M
1676 442M
1768 445M
1930 337,390,351,376,361M,349,391,345,375,362,359,395,339,369,363,354,340,379,353,355,341,381,352,356,338,388,350,377
1945 435M