SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31a93ddd3cf833365a7a7de66eb56129293a60bfae9e265e86ecc336ea96a894' 
  AND token = 'zIo0YlJTXjjBZUj9+U0emdNYb1KOE+MKKeJOsRAo14E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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