Added a test case.
The problem was fixed by the fix for bug #17379.
The problem was that because of some conditions 
the optimizer always preferred range or full index
scan access methods to lookup access methods even
when the latter were much cheaper.


mysql-test/r/select.result:
  Bug #19372: test case.
  The problem was fixed by the patch for bug #17379
mysql-test/t/select.test:
  Bug #19372: test case.
  The problem was fixed by the patch for bug #17379