SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ca687e35b51fdf4ce9faddd95c1bd941fc33ad574f92434ece23780b27e7305' 
  AND token = 'rKMMnYIzNref/YWzoPw6pDUoEIE3YwdSsw8RKnYiQy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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