I have the following query:

ALTER PROCEDURE [dbo].[spSearchClient]     @SearchWords NVARCHAR(MAX) = NULL,     @LowerDate DATE = NULL,     @UpperDate DATE = NULL,     @UserCreated nvarchar(450) AS BEGIN     SET NOCOUNT ON;      DECLARE @UserAccountID smallint     DECLARE @SearchWordCount int      SELECT @UserAccountID = dbo.fnGetUserAccountID(@UserCreated)      CREATE TABLE #SearchWords     (         ID int IDENTITY(1,1),         Word NVARCHAR(50)     )      INSERT INTO #SearchWords     (         Word     )     SELECT          value      FROM          STRING_SPLIT(@SearchWords, ' ')       WHERE          TRIM(value) <> ''      SELECT @SearchWordCount = @@ROWCOUNT;      SELECT         C.ClientID,          C.FirstName,         C.LastName,         C.FullName,          C.DateOfBirth,         G.GenderName,          G.GenderIcon,          C.VerificationCode,         V.LastVisitDate     FROM          Client C     OUTER APPLY (         SELECT MAX(StartDate) AS LastVisitDate         FROM Visit AS V         WHERE C.ClientID = V.ClientID     ) AS V     INNER JOIN LookUp.Gender G on         C.GenderID = G.GenderID     WHERE         (             EXISTS( -- if we have words                     SELECT *                     FROM #SearchWords s                     WHERE (c.FirstName LIKE CONCAT('%',s.Word,'%'))                         OR (c.LastName LIKE CONCAT('%',s.Word,'%'))                         OR (c.VerificationCode LIKE CONCAT('%',s.Word,'%'))                 )             OR @SearchWordCount = 0 --if we don't have words         )         AND DateOfBirth BETWEEN ISNULL(@LowerDate,DateOfBirth) AND ISNULL(@UpperDate,DateOfBirth)      INSERT INTO UserSearchLog     (         SearchWords,         LowerDate,         UpperDate,         SearchResultsCount,         UserCreated     )     VALUES     (         @SearchWords,         @LowerDate,         @UpperDate,         @@ROWCOUNT,         @UserAccountID     )      DROP TABLE #SearchWords END 

The execution plan is https://www.brentozar.com/pastetheplan/?id=BkGzfUeHz

The query works how it should but takes a good 3-7 seconds to run and it seems to all be due to the following which has an execution for every row in the Client table:

WHERE     (         EXISTS( -- if we have words                 SELECT *                 FROM #SearchWords s                 WHERE (c.FirstName LIKE CONCAT('%',s.Word,'%'))                     OR (c.LastName LIKE CONCAT('%',s.Word,'%'))                     OR (c.VerificationCode LIKE CONCAT('%',s.Word,'%'))             )         OR @SearchWordCount = 0 --if we don't have words     ) 

Wondering if anyone knew of a better more effective way of doing this that would be less time consuming?

If some sample data would be useful, please let me know.