Airflow with mysql rabbitmq-server Could not translate host name "postgres" to address: No address associated with hostname

I'm trying to run an airflowjob scheduler with a mysql database and a rabbitmq-server. Everything worked before i changed database.

I changed the airflow.cfg file to:

executor = CeleryExecutor
sql_alchemy_conn = mysql://airflow:airflow@localhost:3306/airflow
broker_url = amqp://guest:guest@localhost:5672/

After creating osme databases with mysql (I followed this guide)

But When I run airflow scheduler I get the following error:

sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) could not translate host name "postgres" to address: No address associated with hostname

Any ideas of what to try?

edit; More info about my settings: I made the database with the following commands:

mysql -u root -p
mysql> CREATE DATABASE airflow CHARACTER SET utf8 COLLATE utf8_unicode_ci;
mysql> create user 'airflow'@'localhost' identified by 'airflow';
mysql> grant all privileges on * . * to 'airflow'@'localhost';
mysql> flush privileges;