There is not a Key command to do that automatically. However, you can use Punch-In recording to do this:
Click on the Auto-Punch button in the Transport (two arrows on it - one up, one down) and adjust the Punch Range in the Bar Ruler (red bar).
Press Record and only the punch-in area will be recorded over.
Did you know you can also protect tracks?
Control click on a track header in the Arrange and select "Configure track header..."
Choose to display "Protect".
You can now click on the padlock to protect a track :)
If you then want to try a different recording without unprotecting the track, choose Track > New with same channel strip/Instrument.