SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d9f3d30b219dba61c945469018bc0354e3c897c758724af20673be62700c417' 
  AND token = 'dmz5fhK68OdAL2z/RHALxxU5D8hwVQNpV20PFikggtE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

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