Be inquisitive about key? That's not worth considering (6)
I believe the answer is:
paltry
'not worth considering' is the definition.
(paltry means insignificant or small)
'be inquisitive about key?' is the wordplay.
'be inquisitive' becomes 'pry' (I've seen this in another clue).
'about' means one lot of letters goes inside another.
'key?' becomes 'alt' (the Alt keyboard button).
'pry' going around 'alt' is 'PALTRY'.
'that's' is the link.
(Other definitions for paltry that I've seen before include "Measly, trifling" , "Trival, Inconsequential" , "not worth considering" , "Trivial or contemptible" , "Feeble" .)