SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a8b1d9a2d41cc49075ea097ab07f18feee346c6facd824029ab62332736c9a71' 
  AND token = 'ZIVD3JaKDnCU56QBp+mNbcDHhGFoWTUMKoAayUtQEwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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