SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0e38185b435157c3f517e6086443c123b5c2f908f7b85dfa3d1f802923acacf' 
  AND token = 'HqDDlJiisavOSjyKayNt5IpFissw4wOdDPS7jUX5QY0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}