SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98d5c230fa48540ccaf112286397fe429a045c2a5a15ff4a4a4ea9b2da37b7a1' 
  AND token = '2Lp9IFnAK8aeD6db8X7jWj3LpBHacob/G+WPPPWMa5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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