grant create routine on tempdb.* to spuser@'localhost' identified by '123456';

delimiter go
create procedure sp_hello_world()
begin
  select 'hello world';
end 
go

delimiter ;

mysql> show grants;
+---------------------------------------------------------------------------------------------------------------+
| Grants for spuser@localhost                                          |
+---------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'spuser'@'localhost' IDENTIFIED BY PASSWORD '*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9' |
| GRANT CREATE ROUTINE ON `tempdb`.* TO 'spuser'@'localhost'                          |
| GRANT EXECUTE, ALTER ROUTINE ON PROCEDURE `tempdb`.`sp_hello_world` TO 'spuser'@'localhost'          |
+---------------------------------------------------------------------------------------------------------------+