SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9991a668ab0b85fd7d6d1185c0efd8909c2a8be397d4805a204efb2da9db570b' 
  AND token = 'oCr+2pAcquMb7WuqSxRw7QXlXYX0C56eRgc1ybgyZ4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables