SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70a9c6b2ecfb643388b644952c5942d77d3647b4922ced4f403b8d31f09789a9' 
  AND token = 'wHdkRBJscvq+8R02SdIuKHlz7zjaMs6T9kYrSSrh+4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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