SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fd8cc620a4b84416c5441cfe77cf644ca46be6850b874109a67aef69e62c7eb0' 
  AND token = 'cBZe6ShS30XTosCI3/n6oINdgklgbEhDllH0pjFPC2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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