Expired matches will appear in the app again, so don't worry - you'll get another chance to match with them. We believe in second chances!
Your expired matches will be shown in your Match queue, and are displayed in silver circles. To rematch with any of these just tap their circle, and then choose Rematch!
Keep in mind that you'll only see expired matches where you didn't send your first message in time. If it was the other person's turn and they didn't send their message, it's up to them to Rematch.