Not awarded mastery token

I just finished an ARAM game where I got an S+ rating, was not awarded a mastery token. I was really looking forward to this because I've had the first token for quite a while now and I even had kept a champion shard to unlock it when I'd have both tokens. I logged out and back in again to see if it was server lag or something but I still only have my first token that I earned a long time ago.