SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54589ca7e578f75e17afcc78f9d22c4e4d6abdadc9055318d9a21f585992780b' 
  AND token = 'vuYo1lz+VUwAqCXCKDWPLz40DWV48sLNA5A2rm54Myk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

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