SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3dca62d67fd99b92aaf55526a9225f56f295533243e054b93f9c7ba2107cd94' 
  AND token = 'yN6FV9ujs1xo9YSe/wUvkJjedUXwXJXKuGUAMTqslKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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