Mr.Moto was the adventurer/detective (played by Peter Lorre) in a series of films between 1937 and 1939. The song is dated 1940, so Mr. Moto may well refer to this character. You can find plenty of net info on Mr.Moto (eg A Guide to the Mr. Moto Films) and this thread has the date for Lyr Add: Java Jive (and other coffee songs)

Mick