Instead of static list, using a table select result for IN key I use a static list for some queries WHERE clause like

WHERE STypeID IN ('12', '13', '14', '265')


This list will be changed in the future; new values will be added. When list changed, I don't want to check all queries which has this list to change, want to control this list from 1 place; so I created a table with two columns; Key and Value, inserted my static values into table. 

      Key             Value

SupportedTypeID        12  
SupportedTypeID        13  
SupportedTypeID        14  
SupportedTypeID        265


I modified my where clause like

WHERE STypeID IN (SELECT Value FROM LOVs WHERE Key LIKE 'SupportedTypeID')


but it causes performance issue; queries results come too late.
In most cases replacement IN clause with EXISTS clause gives performance boost.
Try this:

WHERE exists (SELECT 1 FROM LOVs WHERE value = STypeID )