SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25459355bbe5f7af61d1cad87ee1e1eaa57a9a76f77b808fb785c32c539db100' 
  AND token = 'vkYNOpl6RctiwPdVQ8tmsmtOM4sdakHfLngOapM/BR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

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