pass [0] (see comment above [1]) claims to do that:
show [ --clip, -c ] pass-name
Decrypt and print a password named pass-name. If --clip or -c is specified,
do not print the password but instead copy the first line to the clipboard
using xclip(1) and then restore the clip‐board after 45 (or
PASSWORD_STORE_CLIP_TIME) seconds.
[0] http://www.passwordstore.org/