SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '674c7b4dc2085739ad5bc494e23675cce8e20f46f1b17283b2fdb937f61fdfd7' 
  AND token = 'uCDFfcbzrpKalLPDq0sLkXgROprgvaW0z+RruIqe9Ck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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