Careful to get keys free (10)
I believe the answer is:
deliberate
'careful' is the definition.
(I know that careful can be written as deliberate)
'keys free' is the wordplay.
'keys' becomes 'de' (I've seen this in other clues).
'free' becomes 'liberate' (liberating is a kind of freeing).
'de'+'liberate'='DELIBERATE'
'to get' acts as a link.
(Other definitions for deliberate that I've seen before include "Done consciously" , "Carefully thought out" , "Premeditated" , "Purposeful" , "on purpose" .)