How would you rewrite this query to be MySQL 5.7 friendly? Currently fails due to new GROUP BY rules.

wtf.sql

select * 
  from ebay_order_items 
  where 
    z_shipmentno is null 
    and ExternalTransactionID is not null 
    and orderstatus = 'Completed' 
    and timestamp > '2015-02-25' 
  group by ExternalTransactionID 
  order by timestamp desc

Hat tip to @feketegy for the solution

select extf.* from (
    select ExternalTransactionID
    from ebay_order_items
    where ExternalTransactionID is not null
    group by ExternalTransactionID
) extf JOIN ebay_order_items eoi ON (eoi.ExternalTransactionID = extf.ExternalTransactionID)
where eoi.z_shipmentno is null
and eoi.orderstatus = 'Completed'
and eoi.timestamp > '2015-02-25'
order by eoi.timestamp desc