The song is called THE PEOPLE’S KEY. It was written by Bob Hipkens and recorded by the Central Park Sheiks on their album “Honeysuckle Rose”, Flying Fish FF 026, LP (1976), trk# 8. The album was reissued as a CD in 2006 by Beatball Records, which is a South Korean label.
I found some footage of Richard Lieberson, one of the members of Central Park Sheiks, at a tribute site. There are several songs on the linked youtube page. Mr. Lieberson seems to have been a very talented and well-liked person; it’s a shame that we can’t locate any of his professionally recorded material.