The most common and most likely answer to this crossword clue is the 6 letter word PEEKED
I've seen this crossword clue in The Guardian
P
E
E
K
E
D
More clues leading to the result PEEKED
Buddy explains!

The straight part
We know that "Looked quickly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case looked quickly = peeked.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PEEKED mean?
PEEKED verb- To look slyly, or with the eyes half closed, or through a crevice; to peep.
- To be only slightly, partially visible, as if peering out from a hiding place.
- To retrieve (a value) from a memory address.