SELECT 
  id_path 
FROM 
  cscart_categories 
WHERE 
  category_id IN (
    5, 15, 17, 18, 19, 38, 49, 57, 67, 73, 81, 
    82, 87, 208, 210, 217, 228, 233, 234, 
    235, 236, 306, 318
  )

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_categories",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["category_id"],
      "rows": 23,
      "filtered": 100,
      "index_condition": "cscart_categories.category_id in (5,15,17,18,19,38,49,57,67,73,81,82,87,208,210,217,228,233,234,235,236,306,318)"
    }
  }
}