$ cat /var/cache/nginx/d/be/54a355887f2e4391a6e0cb9150ae3bed
[...]
KEY: https://test/style.css
HTTP/1.0 200 OK
Strict-Transport-Security: max-age=31536000; includeSubDomains
[...]
$ echo -n https://test/style.css | md5sum
54a355887f2e4391a6e0cb9150ae3bed  -