SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cefbcff17077c684e2432750a618285a9cae1062414fe9cfc88676fa0eb5379' 
  AND token = 'RUXoBnDgDk8PXYY9qu6/tw66O/7niGOO9VpIcJj6Tno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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