Using sql functions

Hi,
I am a newbie trying out CLSQL.
I want to be able to use SQL functions like "now()" on a wall-time
field. Currently i am doing the following :

(execute-command (format  nil "INSERT INTO DATA (user_name,  email,
created_on, modified_on)
                                          VALUES ('~A', '~A',  now(),
now())" user-name email))

How can i do this using the CLSQL-READER-SYNTAX ?
Can you point me to relevant documentation, which shows how to user
inbuilt SQL functions like "now()" ? I tried CLSQL documentation, but
could not find much.

(with-database (*default-database* *db* :database-type :mysql)
      (insert-records :into "DATA"
                      :attributes '(user_name email created_on modified_on)
                      :values `(,user-name ,email "now()" "now()")))

The above does not work.

Thanks,
Prashant.