SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '921e348599ac8320f4ef77b8091890d4dfaddf03f5db4116f684371b39af863c' 
  AND token = '7UVhuuMw0zgywPdiKo12NZSXMvb1LnVXcDoSBlYb5mQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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