What criminal might do with key before door's opening - might that prove lucky? (7,4)
I believe the answer is:
scratch card
'opening might that prove lucky?' is the definition.
The definition suggests a singular noun which matches the answer.
'what criminal might do with key before door's' is the wordplay.
I cannot quite understand how this works, but
'key' could be 'd' (musical key) and 'd' is located in the answer.
'door' could be 'car' (car door is a kind of door) and 'car' is found within the answer.
The remaining letters 'scratch' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for scratch card that I've seen before include "one offering prize after scoring?" , "Gambler's investment rubbed with a coin" , "Instant lottery ticket" , "may offer instant reward" , "Expert at golf club perhaps" .)