Its less of an exploit more of a trick so sorry if i posted on the wrong place but anyways
So in order to get 2x quick keys :
1)track down one of the randomly spawned chests on the island ( do not open it)
2)Go kill a rare mob on the island until the corpse has a key on it ( do not loot it)
3)Go back open the chest and loot the key(key no.1)
4)Go back to the corpse of the rare mob and loot the key (key no.2)
Enjoy the 1k extra gold doing the scenario