There is 2 keys in the map, but one of them is a red haring. On the right-side of the map, between trees you find 3 stones on the ground that's the location for the right key.
Hey, I found the right key, what do I do now? Do I need to play a couple rounds with Lyra or something for the next step to trigger?
(I already did the graveyard thing with Syrianna.)
Edit: Oorrr not... The quest is still active apparently... Also I found the next thing for the key.