SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '824522118db4db4a086122045698476970cd10b1c3ed51bbf4fa27694ce42731' 
  AND token = '4IJUvL3pczWk6WC/v02TL7QI1a8vTA5e3oDAZu93jfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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