MySQL: Check if there Exist Row(s) Matching a Condition

I have been doing this for quite some time:

SELECT COUNT(*) FROM Table WHERE Condition = *Condition*;

Since I am not interes开发者_开发技巧ted in the total number of rows returned, I wonder if there is a more efficient way to check if there exist any row(s) that match the condition without letting MySQL scan through the entire table.

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SELECT CASE
         WHEN EXISTS(SELECT *
                     FROM   YourTable
                     WHERE  Condition = '*Condition*') THEN 1
         ELSE 0
       END  

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Try

SELECT COUNT(*) FROM SmallTable
WHERE EXISTS(SELECT * FROM Table WHERE Condition = *Condition*)