SELECT 
  id_path 
FROM 
  cscart_categories 
WHERE 
  category_id IN (
    32, 53, 56, 67, 79, 208, 226, 230, 235, 
    236, 242, 261, 306
  )

Query time 0.00048

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": 13,
      "filtered": 100,
      "index_condition": "cscart_categories.category_id in (32,53,56,67,79,208,226,230,235,236,242,261,306)"
    }
  }
}

Result

id_path
2/10/32
308/3/13/53
308/3/13/56
308/3/13/67
308/3/13/79
308/3/12/208
308/3/13/226
230
308/231/235
308/231/236
308/232/242
308/3/12/261
306