I remember “keystone” but not “keyhole” in a Q drop....
One instance, when "Q" was posting on 4chan. Blockquote below just now cut directly from 4chan, edited to remove "Report" and "quoted by" links.
Thread: CBTS #505 Space XXX Edition Thu 23 Nov 2017 00:30:50 No.150565407
Q !ITPb.qbhqo ID:b+CmIEaI Thu 23 Nov 2017 01:11:25 No.150569482Keyhole.
Happy hunting.
Q