SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5411d05eef0d20f2f3855c033504efccdec68856e74401af5744d5815f676ffc' 
  AND token = '83PYPKUnesn3gQn2TUcxunOm1pwf4+XDdF6IVxD8wyE=' 
  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