SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09f75c3ec8553a040dbf3bfb39a7269e769ae355a2688a84dc888cb3be2a4472' 
  AND token = 'HDogvsywC1mMCQchUHOXHp+vIPYb/LigPX2YGZKMoK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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