SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '822b9e0bbde2fbebb93347f016febbb1f92709a1aae7fcefa5553a5cd6e26568' 
  AND token = 'XHfGgrqbJfvk/CXG4D16s9m/adypcGgxPGponwIyK40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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