Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8934f662dbb7ebdb0df25921b7400d7e4eaae85586aa3ccf29237e7cb8bca49' 
  AND token = 'dq5mJ8YtjLmah6PEkZ9PanWlxOSmlrIpwnR5Ybm+mkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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