SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    312886, 312887, 116523, 312884, 116531, 
    312902, 312899, 312900, 116515, 312904, 
    116535, 312925
  )

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.0216566,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_products",
          "access_type": "range",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "loops": 1,
          "rows": 12,
          "cost": 0.0216566,
          "filtered": 100,
          "attached_condition": "cscart_products.product_id in (312886,312887,116523,312884,116531,312902,312899,312900,116515,312904,116535,312925)"
        }
      }
    ]
  }
}