SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4eb95064cdd3fe10c38803ded0664c2a137a4241c1596576aa531d6f25783966' 
  AND token = 'nYKeIjhEFAxng7vffDZU/n8UaIQoUXWbs8CXdCu3ayY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}