Preside over key and locks (5)
I believe the answer is:
chair
'preside over' is the definition.
'key and locks' is the wordplay.
'key' becomes 'c' (I've seen this in other clues).
'and' says to put letters next to each other.
'locks' becomes 'hair' (I've seen this before).
'c'+'hair'='CHAIR'
(Other definitions for chair that I've seen before include "academic office" , "control meeting" , "Top seat of committee" , "Professorship" , "Lead" .)