SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '515d915d537d48278893886ee9f2adf9a1e70fbbd8cd09269f2c7174132a30de' 
  AND token = 'IFY1WeaOgLGaqKZqB/2iiOk6v+y7B5f4DZseAa4uJmk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}