SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd6b1384f962c19d35b00a348c429214da650f2780d5896cf7734b79e7dca6b1' 
  AND token = 'bT5wuCubRhTmuEnOwUC06dsUySky+Nopx48vS3Ejipc=' 
  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