SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e41855509e4a3615ff791bf0ae0eaeb5b813f2d68609d1e967eb68c208076709' 
  AND token = 'd6AISFl00QHSG63jleqCf4eSw1Gx6kMMWXZWZK4bbRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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