Is there any way I can execute a PHP script from MySQL?

I want to invoke and execute a PHP script from a MySQL procedure. Is this possible?

CREATE PROCEDURE simpleproc (OUT param1 INT)
    BEGIN
         Call my php script here
    END//

[EDIT]
I am in fact trying to raise an event when a condition is met — for instance when my table field value matches the current time. Then, I want to capture the event and send an email.