SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc91202a20c5a06ab78adb87aa9321f8d465e21132b286352543403d06c21642' 
  AND token = '6RxEIzxusoMwDd5gkdrV+foDJHsT1gpEaKPolYiKv8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

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