SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec980b408dd897da8c555044503fd094570b38b7296934db4c27686c52b72374' 
  AND token = 'vCGUTadUK+Uvxy/1Gmghb10LoE8gWCduwu+gnBDo4C0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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