SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a4df4224dc063b84738a1357573a87a060bceb4f5dc9359b860f24803be1d52' 
  AND token = 'WVvZE6g/L0YFYnZ6AEiaVkkXbGvimrrfHYM49CPB/wU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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