SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e164c951eaf3a4a341e2bbb5f78c5a0e02754fdbc891e175075fa0f660609c34' 
  AND token = 'o4mzXVpCl+5Y2mSvYz/EWDXKhinmyVRlrL79VxwjInU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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