SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fd800863fc298bc3c977f189d76af055cbda758279d68e0caa6a9d709f199f1' 
  AND token = 'S4m+wm92jLKjw24XKiVTnmZaJ3xjRBY/+ZSHeDKrAfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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