SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2c2003d4792cce763fd05209ca2af32842b66f49a8e5dbec437635e3f59e5f1' 
  AND token = 'eokjC87YmnGlvv0ekFd59WAqrEhwXPnaoLLEtJL8S04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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