SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '773f2376298346c061b98dfecced115ba8b5132fb9e173cc6b43248f55045a43' 
  AND token = 'hlI2sWhZDk/NXxBL6Q9e+i0SQ69iV+O9YHDXCmpjVzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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