WITH    a6
          AS ( SELECT   cdc.col2
                       ,maxLimit.col15
               FROM     table1 AS cdc
               JOIN     table2 AS cdt  -- comment out this join to get seek
                        ON cdt.col1 = cdc.col1
               OUTER APPLY ( SELECT TOP 1
                                    rules.col11
                                   ,rules.col15
                             FROM   ( SELECT    clr.col11
                                               ,clr.col15
                                               ,Priority = ROW_NUMBER() OVER ( ORDER BY clr.col2 DESC, clr.col1 DESC, clr.col10 DESC, clr.col12 DESC, clr.col13 DESC, clr.col7 DESC , clr.col14 DESC )
                                      FROM      table4 AS clr
                                      WHERE     clr.col7 IS NULL OR clr.col7 = cdc.col7
                                    ) AS rules
                             WHERE  rules.Priority = 1
                           ) maxLimit
             )
    SELECT  a1.[col2] AS [col22]
    FROM    [dbo].[table1] a1
    INNER JOIN [dbo].[table5] a2
            ON a1.[col2] = a2.[col2]
    INNER JOIN [dbo].[table6] a3
            ON a2.[col2] = a3.[col18]
    INNER JOIN [dbo].[table1] a4
            ON a3.[col19] = a4.[col2]
    INNER JOIN a6
            ON a6.col2 = a4.col2
    WHERE   0 < ISNULL(a6.[col15], 0)
            AND a1.col2 = '1234123412341234';