SELECT 
  cscart_products.*, 
  cscart_products.ebay_status, 
  cscart_products.ebay_template_id 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    8326, 8328, 8333, 8342, 8343, 8344, 8345, 
    8355, 8356, 8362, 8365, 8366, 8367, 
    8368, 8370, 8371
  )

Query time 0.00040

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 (8326,8328,8333,8342,8343,8344,8345,8355,8356,8362,8365,8366,8367,8368,8370,8371)"
    }
  }
}