Proper use of WHERE IN using the Record component:
$this->Record->select("service_fields.*")->from("service_fields")->
innerJoin("services", "service_fields.service_id", "=", "services.id", false)->
where("service_fields.key", "=", "hostname")->
where("service_fields.value", "=", $hostname)->
where("service_fields.status", "in", array("active", "suspended", "in_review"));