SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66482d9cbb1cc4de5f4bd1618ec4f10434cd6714c7449971f7c3d43ea53210a7' 
  AND token = 'Q7KuoONlvnYRSOIbQudIlQp1VpoFVcc2qWucLJXQvZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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