SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bd501a5f5a256cb5fbd823c259a82caa0e034aee2007207e48e7b8ae98b28c3' 
  AND token = '5j/yJH5wD6gQX9wipBaqtrru9rDe6zpI4mbbPHb+I7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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