SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c010aa7a5b584e6d2977d990d2c9f3d1f35b16bc9eb8e55bd9c5e64f6058cc7' 
  AND token = 'lxqs+4FrGUGaqJqnOkC5vzwiaTd8YPb+hbrsuRzLhK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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