SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    239, 242, 243, 241, 240, 214, 217, 218, 
    207, 59, 58, 60, 172, 134, 135, 168
  )

Query time 0.00075

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 16,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (239,242,243,241,240,214,217,218,207,59,58,60,172,134,135,168)"
    }
  }
}