how to add key and UNIQUE KEY to existing table without check to speed up performance?
If I understand correctly, you want to achieve improved performance for the restore process of an SQL dump file. In that case, you can use do SET UNIQUE_CHECKS=0; before inserting the data and then SET UNIQUE_CHECKS=1; afterwards.

(mysqldump already does this automatically, at least for MariaDB.)

See also the documentation for bulk loading data.