$productCollection = Mage::getModel('catalog/product')->getCollection()
            ->addAttributeToFilter('type_id', ['eq' => Mage_Catalog_Model_Product_Type::TYPE_CONFIGURABLE])
            ->addAttributeToFilter('status', ['eq' => Mage_Catalog_Model_Product_Status::STATUS_ENABLED])
            ->addAttributeToSelect('some_custom_attribute')
            ->addAttributeToSelect('name');

SELECT `e`.*, `at_status`.`value` AS `status` FROM `catalog_product_entity` AS `e`
 INNER JOIN `catalog_product_entity_int` AS `at_status` ON (`at_status`.`entity_id` = `e`.`entity_id`) AND (`at_status`.`attribute_id` = '96') AND (`at_status`.`store_id` = 0) WHERE (`e`.`type_id` = 'configurable') AND (at_status.value = 1))

foreach ($productCollection as $product) {
            echo "Product is: ".$product->getId()." with name ".$product->getName()." with value of custom attribute ".$product->getSomeCustomAttribute()."n";