Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78fb475b56c0cdf56a018d697fc397f6c2d6fdbdc6991267e7d3829486ed6f90' 
  AND token = 'j1xrERNLqYQEJq6YaHjaDvfxB+sr15n4HMNwNBaLnu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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