SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8653a78e274f16af737e8967c01cb553f24aefcba19e44d306939999f3207aee' 
  AND token = 'nIbZUiQQ7P8ZwTrD5ZlFz71ENGK/muBRBgS9r55hydU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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