bool b = db.t_M_Log
       .Any(w => 
            w.IdUser == 4000000
            &&  w.Token == token);

SELECT 
    CASE WHEN ( EXISTS (SELECT 
        1 AS [C1]
        FROM [dbo].[t_M_Log] AS [Extent1]
        WHERE ([Extent1].[IdUser] = @p__linq__0) AND (@p__linq__0 IS NOT NULL) AND ((([Extent1].[Token] = @p__linq__1) AND ( NOT ([Extent1].[Token] IS NULL OR @p__linq__1 IS NULL))) OR (([Extent1].[Token] IS NULL) AND (@p__linq__1 IS NULL)))
    )) THEN cast(1 as bit) WHEN ( NOT EXISTS (SELECT 
        1 AS [C1]
        FROM [dbo].[t_M_Log] AS [Extent2]
        WHERE ([Extent2].[IdUser] = @p__linq__0) AND (@p__linq__0 IS NOT NULL) AND ((([Extent2].[Token] = @p__linq__1) AND ( NOT ([Extent2].[Token] IS NULL OR @p__linq__1 IS NULL))) OR (([Extent2].[Token] IS NULL) AND (@p__linq__1 IS NULL)))
    )) THEN cast(0 as bit) END AS [C1]
    FROM  ( SELECT 1 AS X ) AS [SingleRowTable1]