Went slowly, but with credit, at a key point (5)
I believe the answer is:
crept
'went slowly' is the definition.
(I've seen this in another clue)
'with credit at a key point' is the wordplay.
'with' says to put letters next to each other.
'credit' becomes 'cr'.
'at' says to put letters next to each other.
'a key' becomes 'e' (I've seen this in other clues).
'point' becomes 'pt' (abbreviation for point).
'cr'+'e'='cre'
'cre'+'pt' is 'CREPT'.
'but' acts as a link.
(Other definitions for crept that I've seen before include "Moved slowly and carefully" , "cringed" , "Sneaked" , "was obsequious" , "Went stealthily or furtively" .)