select 
s.bis_lot as lotcode,
l.lot_desc as lotdescription
FROM r5binstock s, r5lots l 
WHERE s.bis_part = <part_code> AND        
s.bis_part_org = <part_org> AND        
s.bis_store = <store_code> AND        
s.bis_bin = <bin_code> AND        
l.lot_code = s.bis_lot