SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77221ed4426c142b42b66c44e8cb78df5eb88898e5acf62ffeedaa9310f13e40' 
  AND token = 'WRxu4+xXsmMvortKlUkhfu/4BZtSfHOrQCvtUajmJ9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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