SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff475c1b4c2dfe4c1a8b655bdf9e023e19b6b139b9b39e820abc7d523c2b8eae' 
  AND token = 'DgkbppEmwKxGNNrQBNYqYUtMNyWkYnvW+S++FJZpHMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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