SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dbb198198c26520cc1f713afaebcf9022f2720dd4bd43586d63eca7362183e9' 
  AND token = '8ZMilCIPrYT7a79jXzIrHY/ysqsh07FvLvLGJXfAYnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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