CREATE PROCEDURE test (field1 varchar(4), field2 varchar(4), array varchar (255))

...
WHERE some_field IN (array)
...

mysql> select find_in_set(2, '1, 2, 3');
+---------------------------+
| find_in_set(2, '1, 2, 3') |
+---------------------------+
|                         0 |
+---------------------------+

mysql> select find_in_set(2, '1,2,3');
+-------------------------+
| find_in_set(2, '1,2,3') |
+-------------------------+
|                       2 |
+-------------------------+

WHERE some_field IN (select array_id from temp_table)