title: race condition in mysql select sql
body: <p>What I try to accomplish seems simple,</p>
  
  <p>Db type: MyISAM<br>
  Table Structure: card_id, status<br>
  Query: select an unused card_id from a table, and set the row as "used". </p>
  
  <p>Is it race condition that when two queries running at the same time, and before status is updated, the same card_id is fetched twice?</p>
  
  <p>I did some search already. It seems Lock table is a solution, but it's overkill to me and need Lock Privilege. </p>
  
  <p>Any Idea?</p>
  
  <p>Thanks!</p>