Visual Studio find out what command is assigned to an hotkey

You can try to assign this shortcut to another command and then you will receive info that this shortuct is already used by [your command]:

The Keyboard Shortcut Extension can help. It produces a text file with a block of entries listing all your current shortcuts like this:

<command shortcut="Ctrl+M, Ctrl+E" name="Edit.ExpandCurrentRegion" />

You can then search for the command in the exported file using the shortcut.

Keyboard Shortcut Explorer