Turning keys in Scottish island (4)
I believe the answer is:
skye
'scottish island' is the definition.
(I've seen this in another clue)
'turning keys' is the wordplay.
'turning' is an anagram indicator.
'keys' anagrammed gives 'SKYE'.
'in' acts as a link.
(Other definitions for skye that I've seen before include "somewhere off Scotland's west coast" , "Scotland island" , "Scots isle" , "Inner Hebridean isle" , "Portree's isle" .)