SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ba8ebd1434d8b0ba541fcd0bf5cfc837f4794ee16011c933c43d87cb409ff59' 
  AND token = 'RfezSClYxspDL7gHEiyg5t4c2A2ecQiNEYuPJO5PWjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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