SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcf0d7782ca552a11e3bf8178439d360ec5084c86612f1455e7425780533b2f0' 
  AND token = 'OtGd2LTkcXMT+gYjGqZ2MO786SoYaPfRMLjDE+HODD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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