SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73452430191517755db6933ef2b97e7995a69f668253b20404ab30041c0bed78' 
  AND token = 'bND07YqZKrpyG+WvHyAT8AtrWRX8dHActkTJp3xeJHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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