Better you will try this below code:
$connection = Mage::getSingleton('core/resource')->getConnection('core_read');
$sql = "SELECT * FROM <table-prefix>_catalog_product_entity_text WHERE attribute_id=(SELECT attribute_id FROM <table-prefix>_eav_attribute WHERE attribute_code='meta_keyword') AND value LIKE '%$metaData%'";
$products1 =$connection->fetchAll($sql);