SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddec33cca609d6f581f28009100aa042c4aa359ebaf42e462707636ab1a9e3fa' 
  AND token = 'rnutXuJArwGTLF9MwcGZdroOiKDXg/0KlRTQy3WI8AU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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