SELECT 
  id_path 
FROM 
  cscart_categories 
WHERE 
  category_id IN (
    5, 6, 10, 61, 67, 73, 79, 82, 88, 281, 306, 
    315
  )

Query time 0.00039

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": 12,
      "filtered": 100,
      "index_condition": "cscart_categories.category_id in (5,6,10,61,67,73,79,82,88,281,306,315)"
    }
  }
}

Result

id_path
5
6
2/10
308/3/13/61
308/3/13/67
308/3/13/73
308/3/13/79
308/3/13/82
308/3/13/88
275/281
306
315