$> git annex version
git-annex version: 6.20160126+gitg65f4442-1~ndall+1
...
$> man git-annex-checkpresentkey | head
git-annex-checkpresentkey(1)               General Commands Manual               git-annex-checkpresentkey(1)

NAME
       git-annex-checkpresentkey - check if key is present in remote

SYNOPSIS
       git annex  key remote