If your tourist visa has expired, the fine must be paid before departure, as this is not possible at the airport, but only at the bank.
When paying, carefully count the days of overstay, including the day of departure. There have been cases where the visa was delayed by less than a day and they were not allowed to board the plane at passport control nor they were allowed to pay the penalty at the airport.
If you have not yet had time to pay for the delay via the bank, ask the passport control officer receipt on departure and say that you will pay on your return. Note that a penalty will apply until your payment is received in the system. Be sure to keep the receipt, it may still be required a few years later.