SELECT 
  q_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      q_products_categories.link_type = "M", 
      CONCAT(
        q_products_categories.category_id, 
        "M"
      ), 
      q_products_categories.category_id
    )
  ) AS category_ids 
FROM 
  q_products_categories 
  INNER JOIN q_categories ON q_categories.category_id = q_products_categories.category_id 
  AND (
    q_categories.usergroup_ids = '' 
    OR FIND_IN_SET(0, q_categories.usergroup_ids) 
    OR FIND_IN_SET(1, q_categories.usergroup_ids)
  ) 
  AND q_categories.status IN ('A', 'H') 
WHERE 
  q_products_categories.product_id IN (
    41334, 41335, 41336, 41337, 41338, 41339, 
    33089, 33090, 33091, 33092, 33093, 
    33094, 33095, 33096, 33097, 33098, 
    33100, 33101, 33102, 33103, 33104, 
    33105, 33106, 33107, 33108, 33109, 
    33110, 33111, 33112, 33113, 33114, 
    33115
  ) 
GROUP BY 
  q_products_categories.product_id

Query time 0.00069

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "201.01"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "q_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 65,
            "rows_produced_per_join": 65,
            "filtered": "100.00",
            "index_condition": "(`portal`.`q_products_categories`.`product_id` in (41334,41335,41336,41337,41338,41339,33089,33090,33091,33092,33093,33094,33095,33096,33097,33098,33100,33101,33102,33103,33104,33105,33106,33107,33108,33109,33110,33111,33112,33113,33114,33115))",
            "cost_info": {
              "read_cost": "110.01",
              "eval_cost": "13.00",
              "prefix_cost": "123.01",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        },
        {
          "table": {
            "table_name": "q_categories",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "portal.q_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 13,
            "filtered": "20.00",
            "cost_info": {
              "read_cost": "65.00",
              "eval_cost": "2.60",
              "prefix_cost": "201.01",
              "data_read_per_join": "34K"
            },
            "used_columns": [
              "category_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "(((`portal`.`q_categories`.`usergroup_ids` = '') or find_in_set(0,`portal`.`q_categories`.`usergroup_ids`) or find_in_set(1,`portal`.`q_categories`.`usergroup_ids`)) and (`portal`.`q_categories`.`status` in ('A','H')))"
          }
        }
      ]
    }
  }
}