SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaa65a9166446139b6bcc47c929034ac206ad4b4d7f696d2da23aaa611ec1630' 
  AND token = '+ud18bvWNp36KZXdXExBuaBqDL5Djf3ZSSHPusql8Zc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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