SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d6d0a369cf89e3c49f7477dbf6211f56899ff57fe0df8fad05aebd0edd3bc04' 
  AND token = 'v1vIbuayTSvTsmLlfVOP0uir7XEb7k++gkF1Vb7IIdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

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