SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d89acc639ae420c5da60e6a579a6409a0041fbdd8d804b65482926add848825' 
  AND token = 'TcHGghyeKNYnAZci5fmSmfy1aNzZKXQ4lO9+XSAxKBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}