SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9aa556a85a665d39c2e0fe33b5ba9996731df84d6614103b01da42a49d2f1f60' 
  AND token = '3yqeEfE0pi2XudyvvEhx+reCHB21uNiqQtU2u7lf710=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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