After a short time that lot will embrace study — keen to get going? (2,3,5)
I believe the answer is:
at the ready
'keen to get going?' is the definition.
(at the ready means ready or eager to start)
'after a short time that lot will embrace study' is the wordplay.
'after' means one lot of letters go next to another.
'short time' becomes 't' (abbreviation for time).
'that lot' becomes 'they' (those people).
'will embrace' indicates putting letters inside (inserted letters are held or embraced).
'study' becomes 'read' (synonyms).
'they' going around 'read' is 'theready'.
'a' put next to 't' is 'at'.
'at'+'theready'='AT THE READY'
(Other definitions for at the ready that I've seen before include "Poised for action" , "dipping hand in till?" , "Prepared for instant action" , "on standby" , "Available for use in operating" .)