SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69dd5e74c9eaf60987e507919e877bc363757302f28dc692eb9609aae519d498' 
  AND token = '/qvNSuZfe+D79VZn+7BvnROiqljxgbIL42MwLHvC8Eg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}