SELECT 
  category_id, 
  parent_id 
FROM 
  categories 
WHERE 
  parent_id IN(
    157, 170, 131, 147, 154, 13, 138, 171, 
    155, 132, 168, 16, 139, 148, 165, 156, 
    133, 172, 17, 149, 169, 18, 173, 134, 
    150, 137, 135, 81, 19, 136, 143, 175, 
    15, 144, 82, 11918, 326, 11913
  )

Query time 0.00083

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "15.87"
    },
    "table": {
      "table_name": "categories",
      "access_type": "range",
      "possible_keys": [
        "parent"
      ],
      "key": "parent",
      "used_key_parts": [
        "parent_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 76,
      "rows_produced_per_join": 76,
      "filtered": "100.00",
      "using_index": true,
      "cost_info": {
        "read_cost": "8.27",
        "eval_cost": "7.60",
        "prefix_cost": "15.87",
        "data_read_per_join": "198K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ],
      "attached_condition": "(`goimagine`.`categories`.`parent_id` in (157,170,131,147,154,13,138,171,155,132,168,16,139,148,165,156,133,172,17,149,169,18,173,134,150,137,135,81,19,136,143,175,15,144,82,11918,326,11913))"
    }
  }
}