SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'debffd4bf654641858b5b79a59d9d9bd21d141730a4f28a3987d776bd19198ec' 
  AND token = 'sYzjuQHqXQLxKZAZ7gYaVZzoGUhg5VW8LrwO27oF2s8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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