SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b62d352bfb83763967537a47af65109253212ade2ecbf90c9ba2b4582d617210' 
  AND token = 'v8A+QM37gKpipdwL+0lXvVze4Y8IEztilyLzoS7y5HM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00120

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