As if by magic, the osprey flies (3,6)
I believe the answer is:
'as if by magic' is the definition.
'the osprey flies' is the wordplay.
'flies' is an anagram indicator.
'theosprey' with letters rearranged gives 'HEY-PRESTO'.
(Other definitions for hey presto that I've seen before include "that's the trick" , "Conjurer's exclamation" , "Spell words" , "Magic words" , "Conjuror's exclamation at the climax of a trick" .)