¿Cómo ejecutar dos consultas de actualización en el programador de eventos mysql?

Prueba esto:

DELIMITER $$
CREATE EVENT update_status
ON SCHEDULE
    EVERY 2 MINUTE
DO
BEGIN
    UPDATE
       customer_group      
    SET
       is_status = 0      
    WHERE
       CURRENT_TIMESTAMP BETWEEN start_date AND end_date;      
    UPDATE
        customer_group       
    SET
       is_status = 1      
    WHERE
        CURRENT_TIMESTAMP NOT BETWEEN start_date AND end_date;
END $$
DELIMITER ;