SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbb7e4a011b6f105d3d769a85e33a6f3b19f28d074a7425222bf2245ce3ad98e' 
  AND token = '6BoOxZH9FRovjAsDM8w9mzwhpTjm9V5Bz2DXU/yYI5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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