Toka is a hardy variety for really chilly places - USDA zones 3, 4 and 5 kinda places. It is a good pollinator for OTHER plums, but don't think it needs a pollinator. Here's what Dave Wilson Nursery has to say about them:
TOKA PLUM Cross between wild plum and apricot plum. Small to
medium sized, dark cherry colored, semi freestone plum. Yellow flesh is
firm and tangy. Introduced from S.D. in 1911. Excellent pollenizer for
Japanese, American and hybrid plums. Cold hardy. USDA Zones 3-8.

Not sure where your location is, but it may do just fine for you if you get enough chill hours. I would contact DWN to see if it will produce in your area with your chill hours (be sure to provide them with your location and chill hours estimate). Or, you can post this on the Fruits & Orchards Forum to see if any of our chiller gardeners can give you an idea of whether or not this plum might still produce for you based on your chill hours.

Patty S.