SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af9d2a96811b984a2cb7b621fc7c63b1437569387435418980778ee5f2d8b9d5' 
  AND token = 'zmJYnVJGYT6qol3sxlaunB42WKW41s/3ubWcmGuKH/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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