SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d3764df23f5d93bdda7357df7b5f25949fb50b9c3ac9dff3fa78e6c2633dbf9' 
  AND token = 'r8L0o66ze17JSjjcjo4hbM9ErrFXs2fw8QhWkJjgDZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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