Firebird query takes unusually long time to process

I am executing following query which contains 3000 conditions inside in operator.

select * from Orders a where a.key 
 in(101,155,16,45,778,9,8,67,1,44,455,56,88,888,8888,88888,77777,77,78, 3000) 

Number of numeric values inside in is 3000. This query is working very slow and sometimes it throws an exception. Is there any other way to write this query.