I can back @inthrustwetrust up with not flushing the transmission. The places that flush transmissions don't typically change the filter. My mom went in for a flush last year, and the guy had the audacity to tell her that her transmission didn't have a filter. So that means all the crap their "flushing" out of the transmission is getting all up in the filter and clogging it. 

Just change the fluid in the pan and change the filter.

Lookup the recommended interval from Toyota in your owner’s manual. 

However that’s pretty low mileage and I would go ahead and change it. But don’t flush it! Use the correct type of transmission fluid as mentioned in your owner’s manual.