SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16e74baee104d6947c4f15e4dfee97f52620cddb217db57e07370be612e8c04a' 
  AND token = 'KTNnQ88Ug3ieSCjLKZwv3MVKptAolhLj+Xnqa0ReT/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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