Has an AFL game ever ended 45-7?
Exactly once. On June 19, 1915, Carlton beat St Kilda 45-7, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 45-7 in league history.
That makes 45-7 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 46-7 has happened never and 45-8 has happened never.