SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89572e92b20746097bdd454e867d8cf811607ba014fec1533b701a57b2d1fd7d' 
  AND token = 'y8L/KoLNMKbLOCbkCRt6q5zzzeGt6oxl4V6GQtopGmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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