SELECT 
  id_path 
FROM 
  cscart_categories 
WHERE 
  category_id IN (
    12, 43, 67, 191, 217, 228, 233, 234, 239, 
    259, 306
  )

Query time 0.00030

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": 11,
      "filtered": 100,
      "index_condition": "cscart_categories.category_id in (12,43,67,191,217,228,233,234,239,259,306)"
    }
  }
}

Result

id_path
308/3/12
308/3/12/43
308/3/13/67
2/10/191
217
228
308/231/233
308/231/234
308/232/239
308/3/12/259
306