SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97700d56df7a4f534f05d113bf108c4eddc13f6bed95f88fe42fb9d475935731' 
  AND token = 'TvMqpIuUDlbjLMvwJhdiHXq/Cj9aQUOaLOKBCuyA0HY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00067

JSON explain

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