Access cookies.sqlite-wal file

I want to export all cookie data when Firefox still runs. The cookies.sqlite file doesn't contain all cookies. Some of them seems to be stored in another file, cookies.sqlite-wal.

When I in Terminal write

/home/kristoffer/.mozilla/firefox/http://ift.tt/1DutBS1 'select * from moz_cookies'

...I get "Error: file is encrypted or is not a database".

Do you know how to access the data in cookies.sqlite-wal?