SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '822088f78537b91e31cdbeb6feab817603dd2647af5bbba74158b1a7ae00b644' 
  AND token = 'ZAbjmsOFxU9WsY95shviukeHrvGfqVyiI5UAZXKuM68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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