I have SQL code that is executing slow

DECLARE @ccode varchar(500)
SET @ccode = '%NIP%'


SELECT  [CVN_UID]
  FROM [Klasje].[dbo].[VERSION_CATEGORY_XREFS]
 WHERE DESCRIPTOR_TEXT LIKE @ccode

Why sql server uses Nested loops?

This code is working fine, it uses only index scan:

SELECT  [CVN_UID]
  FROM [Klasje].[dbo].[VERSION_CATEGORY_XREFS]
 WHERE DESCRIPTOR_TEXT LIKE '%NIP%'