SELECT 
  cscart_products.*, 
  cscart_products.ebay_status, 
  cscart_products.ebay_template_id 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    10766, 10767, 10768, 10776, 10781, 10789, 
    10791, 10792, 10793, 10796, 10797, 
    10801, 10806, 10807, 10812, 10815
  )

Query time 0.00039

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 (10766,10767,10768,10776,10781,10789,10791,10792,10793,10796,10797,10801,10806,10807,10812,10815)"
    }
  }
}