SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25ed8d1eaca8b7f80509a13f8e187926555710f64d6c14b46e6f1de0f300b343' 
  AND token = 'kL3ZkVu0srEjOKcfPTeazAxeEYi1Z6t+GB5tiYmcN0M=' 
  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