SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '575e222f337ac998f91ed655787faa6ea4aaf558e7a92a555b312e2680d2b9b7' 
  AND token = 'QuEaNFkMmOZiii8S2AlpRTk4yVNsDsBqF9Ql5Q70wuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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