Mysql has a MICROSECOND function but none of the functions that get the server time (NOW(), SYSDATE(), UNIX_TIMESTAMP()) contain a microsecond value, at least on my server (I test using SELECT MICROSECOND(various functions here...);.) So, I believe that mysql will not do this for you.
PHP has a microsecond() function that is typically used for this. I don't know if the perl functions you mention are the equivalent to this...