SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '587b24f6fc8ec2251e1c70ecc26bee3ce148d8afab9a68d58aa731a8a6ee30de' 
  AND token = 'ZKy/Gx4u73yCiNsFlOvA6lOlKFKf/bm4M8HhKIQSikA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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