SELECT 
  id_path 
FROM 
  cscart_categories 
WHERE 
  category_id IN (
    1, 16, 27, 47, 62, 67, 114, 118, 123, 181, 
    206, 235, 238, 257, 261, 306
  )

Query time 0.00040

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": 16,
      "filtered": 100,
      "index_condition": "cscart_categories.category_id in (1,16,27,47,62,67,114,118,123,181,206,235,238,257,261,306)"
    }
  }
}

Result

id_path
1
2/7/16
2/9/27
308/3/12/47
308/3/13/62
308/3/13/67
308/3/14/114
308/3/13/118
308/3/14/123
308/3/13/181
2/8/206
308/231/235
308/231/238
275/257
308/3/12/261
306