SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9bcc58885423ac49cda3b90ef9b81517646dae003d49a7c60c7d65c8b7bb8c6' 
  AND token = 'nbLhLxiAewhvwPovtKpxuogorHgJVsqHzd4j8OVAhQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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