SELECT 
  cscart_products.*, 
  cscart_products.ebay_status, 
  cscart_products.ebay_template_id 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    8450, 8451, 8456, 8459, 8462, 8464, 8466, 
    8470, 8476, 8477, 8478, 8479, 8490, 
    8491, 8498, 8499
  )

Query time 0.00045

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 (8450,8451,8456,8459,8462,8464,8466,8470,8476,8477,8478,8479,8490,8491,8498,8499)"
    }
  }
}