Yes you get 5.35%, but you first have to buy $ and at the end of the term exchange them to baht again.
The difference between buying and selling rate is about 2%, so that is already only 3.35% left, and that is if the dollar remains stable.
Have you looked at the exchange rate this week?
And I forgot, I guess that interest is subject to 15% withholding tax, so with the baht getting stronger, and the withholding tax, your 5.35% may actually be a negatvive end result