Ok, I tried the same query on an old version of Toad. This time I got an error message (ORA-3120), rather than a hang. Seems the new version is either gobbling up or totally unaware of the error message beign returned from Oracle.
I used Ctrl-Enter. Just tried F9: same thing. I.e. emty data grid, and the in-progress runner at the bottom right just keeps on going. Surely, 2:21 (and still counting) should be ample time to respond to this query!