SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61d090249fe6cb979199608dc2267586f517e036179ef878360a8bfffe4bf139' 
  AND token = 'UChiK6a3qC47u/xe4lzh59jcLOLej7CGsJy7qZCEq8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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