SELECT 
  category_id, 
  parent_id 
FROM 
  q_categories 
WHERE 
  parent_id IN(
    301, 7, 470, 407, 249, 408, 61, 264, 6, 
    257, 217, 567, 207, 248, 615, 406, 598, 
    484, 243, 469, 614
  )

Query time 0.00081

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "154.01"
    },
    "table": {
      "table_name": "q_categories",
      "access_type": "range",
      "possible_keys": [
        "parent"
      ],
      "key": "parent",
      "used_key_parts": [
        "parent_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 95,
      "rows_produced_per_join": 95,
      "filtered": "100.00",
      "index_condition": "(`portal`.`q_categories`.`parent_id` in (301,7,470,407,249,408,61,264,6,257,217,567,207,248,615,406,598,484,243,469,614))",
      "cost_info": {
        "read_cost": "135.01",
        "eval_cost": "19.00",
        "prefix_cost": "154.01",
        "data_read_per_join": "250K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ]
    }
  }
}