How to query metrics for a specific time

When I run this curl command containing the PromQL query:

curl -s -G "" --data-urlencode "query=http_requests_total @ 1685668320" | jq

I get a response with this value:

"value": [1685668929.444, "406335"]

Shouldn’t the time value from the response be 1685668320? Or does it get the closest value to it?

I’m not sure the query syntax is correct but I did follow instructions from here: