SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93151cffbd9726193e29865be96ae091fd753fca40f9428d6af79bbdc1d5f8cd' 
  AND token = '+jGhEwP6Sv+nCRoqZ17Udwp0C0Hb9DSoWH2l1AYYRPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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