SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16e72d733221c7ad2ecd62e2334fb3beb1050b345dee528111b2c88be9aed435' 
  AND token = 'C1zEMx81ok9gT3+p3htnTrK9e5Wxpc6fQ+B9wV0vJCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

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