I like it. The work-around is to switch screens either by opening the map or tech tree and then coming home to see if the "Keys have appeared" message pops which isn't fun.
Voting YES
The "keys have appeared" notification stays on screen sooo briefly that it is easy to miss it just looking away for two moments. Knowing that, I [obsessively-ish] do a perimeter sweep "just in case" and switch to a screen as you described and coming back. If no message, then I'm satisfied, until the next time I look away for more than ten seconds. *sigh*
It would be nice if I could just forget about it and ignore their possible existence and check hourly (or whatever) and let it go inbetween... but that hasn't happened (which might be helped if I understood the drop schedule, but I'm doubtful that would really solve the fixation "problem").
It is a pinch worse (speaking for me) in this particular event because I'm finding I have to look harder to find the keys that are too much like the landscape. A purple halo would have done a lot to help this. The gold seems like it should stand out but I find it too similar to the yellow-greens mixed with the multi-shaded textures (don't get me wrong, I love the art, it's just the keys blend a bit more than I'd like). On mobile, I'm finding keys less difficult to see because they are out of proportion against the background, much larger and stand out well. On desktop, where I prefer to be, they are very small and blend a bit more.
A counter would relieve so much of that irrational angst generated by the task of collecting the keys.