SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35059d8a229c707559f5a3bc741ce9c5b90b8d98c7d71eb46d332a9ee447ffaa' 
  AND token = '6sP9i7X7xwI3JVkP1fEAZSYo8yOY0WIo+ww9YaxKWtM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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