SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4623136b152fc600ccf1a4c60d69bde42154e671949d57ec7a55a0a35a51ba4' 
  AND token = 'Tc3w4gPUasKM4JGjhWVameMe1/MkUnIpPQCWYdLfkc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

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