SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7b71d9e3f09fb4b238108574e17b897fab81f69717382f35350c86651b297a0' 
  AND token = 'Rrnd4OH1zJ9zdrzfWh85zHRcr6PiQPbZrdCFy/q27uY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

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