[exim] how to avoid a lookup defer in a router

Hi guys...

Shouldn't this router just be skipped if mysql server is down?

scan:
driver = accept
local_part_suffix = +*
local_part_suffix_optional
condition = ${if eq {${lookup mysql{SELECT action FROM bwlist WHERE
(id = '$local_part$domain'}{$value}{NOSCAN}}}{SCAN} {yes}{no} }
transport = send_to_spamd
no_verify


The router is just deferring when mysql is down... But the same doesn't
happen in a very similar '${if' statement with a mysql query that feeds
an ACL variable in SMTP time.

Any ideas?