MariaDB [test]> create table t (i int);

Query OK, 0 rows affected (0.11 sec)

MariaDB [test]> insert into t values (1),(2),(3);

Query OK, 3 rows affected (0.03 sec)

Records: 3  Duplicates: 0  Warnings: 0

MariaDB [test]> DELIMITER //

MariaDB [test]> CREATE OR REPLACE  DEFINER='root'@'localhost' PROCEDURE simpleproc (OUT param1 INT)

    ->  BEGIN

    ->   SELECT COUNT(*) FROM t;

    ->  END;

    -> //

Query OK, 0 rows affected (0.03 sec)

MariaDB [test]> DELIMITER ;

MariaDB [test]> CALL simpleproc(@a);

+----------+

| COUNT(*) |

+----------+

|        3 |

+----------+

1 row in set (0.00 sec)

MariaDB [test]> select version();

+----------------+

| version()      |

+----------------+

| 10.2.8-MariaDB |

+----------------+

1 row in set (0.00 sec)