models.py

    statement = ( 
        "UPDATE {db_name}.user_store USING TTL %s SET clear_pending = True"
        " WHERE user_id = %s IF EXISTS"
    ).format(db_name=settings.DATABASES['default']['NAME'])

    execute_statement(statement, (CLEAR_PENDING_TTL, user_id))
    
    ...
    
    def execute_statement(statement, params, **kw):
        session = connection.connection.session
        return session.execute(statement, params, **kw)