I don't always have keys in inventory while out and about. I've curiously noted ( at least in my brain) that when I dont have any a multitude of chests seem to spawn along my path.
And when I do have keys , it seems I have to seek them out as opposed to just having them there as Im walking along my path.
I'm not a chest runner by any means, just something I think I've noticed lately. I'm sure there may be some science behind it.