Small key locking in a painting (8)
I believe the answer is:
seascape
'painting' is the definition.
(seascape is a kind of painting)
'small key locking in a' is the wordplay.
I cannot quite see how this works, but
'small' could be 's' (abbreviation - e.g. clothes size) and 's' is found in the answer.
'key' could be 'e' (I've seen this in other clues) and 'e' is present in the answer.
'a' is present in the answer.
The remaining letters 'scape' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for seascape that I've seen before include "Painting genre" , "View of the main" , "Marine view/picture" , "Coastal or ocean view" , "Ocean picture" .)