SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c005509a4b9f0863d25694f6349c6113f37956ebe9009e3e070e58b56dd33b99' 
  AND token = 'PvnbYyGj6eSjJqhXZKzTFlipHoDSxRUPLGIGiQQYDdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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