SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03734a4bf380222041cb159d98f6c95fc4208cfe514dd5e53ce34d735b0cf71f' 
  AND token = 'ptE/6x2RFlp2TTXNfTmgjwtlfh2X27xmsFUn4f1GwOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

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