SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f47cd426bc7355856b894389410f542571f75c7630889d1a1bb9614d65a375f' 
  AND token = 'IgO/FCAb32HIHA+kTw3+qRoS6Mgik2Qvur+Y/o3jWjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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