SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ca9e9053e6653b12b99ea20e99a1d99d7b20e8863743fa7eea41535d329a33f' 
  AND token = 'hOf5Z/4hVVh4p3N5RHB754/A1y7StDcUMdUrFUc1sVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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