SELECT ... INTO ...
only works if the table specified in the INTO clause does not exist – otherwise, you have to use:
INSERT INTO dbo.TABLETWO
SELECT col1, col2
FROM dbo.TABLEONE
WHERE col3 LIKE @search_key
This assumes there’s only two columns in dbo.TABLETWO – you need to specify the columns otherwise:
INSERT INTO dbo.TABLETWO
(col1, col2)
SELECT col1, col2
FROM dbo.TABLEONE
WHERE col3 LIKE @search_key