SELECT 
  cscart_products.*, 
  cscart_products.ebay_status, 
  cscart_products.ebay_template_id 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    18717, 18718, 18719, 18720, 18721, 18722, 
    18723, 18724, 18725, 18726, 18727, 
    18728, 18729, 18730, 18731, 18732
  )

Query time 0.00043

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 (18717,18718,18719,18720,18721,18722,18723,18724,18725,18726,18727,18728,18729,18730,18731,18732)"
    }
  }
}