SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e72d253103528d03da044c6c3ee4c3943c8d975b7f5b84b17889a371c6adf8b' 
  AND token = 'rSi+nOMAqnTqecwiC4SZJyh6qFQaVfwsd1zuIsJHlUI=' 
  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"
    }
  }
}