SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '784524d045e8d1774d14792a24db8f09d2f8ad87a5ed10bf2575d7f751cd5bbd' 
  AND token = 'jdPfnGbKKO7tQrx3Uu41a/IjN87eizD721NCBOfmVfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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