If an APK is labeled "for Android TV", will it work with stock mobile phones? I am looking for an APK for a specific application, and I found two APKs, both of which have the same version, but one has the minimum version 2.3 and the other has the minimum android version 5.0 and has the label "for Android TV". 

The mirror I am browsing says that the former is "outdated" in favour of the latter that has the label "for Android TV". Does that mean that I have to take the latter, even though I am not using Android TV, for a mobile phone? Or should I take the former, which has the same version albeit a lower minimum-android version requirement.
No, It simply won't work for a stock android phone. Because the app was created with a tv's resolution in mind so all you would see is misaligned screen or force crash.