Google the inscription on the token and you'll get some interesting results.
St.Athan is a Royal Air Force base in South Wales.
Here is a website of military tokens which has yours
https://sites.google.com/site/malstokens/raf
I even found a couple of old sales of such a token: one for 22 pounds and another for about 10 cents.
I collect coins and tokens which circulated in Africa from 18th century to 2000. I sell about 7000 illustrated world coins from
http://www.avscoins.com.