If you are aware of the HashKey, then any query will return the items sorted by Range key. This is an extract form AWS Documentation:
"Query results are always sorted by the sort key value. If the data type of the sort key is Number, the results are returned in numeric order; otherwise, the results are returned in order of UTF-8 bytes. By default, the sort order is ascending. To reverse the order, set the ScanIndexForwardparameter to false."
So, i don't think its possible to order the results of scan