According to AY website a flight marketed by AY should qualify:
When you start your journey at Helsinki Airport, you are allowed to use the Priority Security lane if
- you have bought a Finnair Business, Business Saver or Pro ticket OR
- you are a Finnair Plus Platinum, Gold or Silver member and you’re travelling on a Finnair marketed flight (the flight number on your ticket begins with an AY-code).
https://www.finnair.com/fi/gb/inform...curity-control