SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b3d4b871bc80884c1e39501989a1ba4c99b3f34bc7361c21d5e5da38e7a030f' 
  AND token = 'RwyTUc6zZ351Pj2kDsatUNpWeJuE36HDs0Pqkr2YeHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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