SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a2167232ba06b07d8ce6fc73837ed7133fb9ca0471dcc97ef577bd67d8304dc' 
  AND token = 'tirLQJL5hYgyYZpqY4FO+RgKg5/iN6I+gooJqWPW9Mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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