SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e08168644539ca43a00df9bab2936f1902ca3370835348b33e4d473eb12e0127' 
  AND token = 'Dpc4Le1VX5s3fJ/wpzDhDqS2kg0640l2vOnGIUnkua0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

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