SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da57d5f8826785ddd8196cf54784cc68806bf65b519842e0bd9e6cb3a04fb499' 
  AND token = '55P9847zY8GmnIOrZCyCVVTaHrEYQmON6J8/odmdOaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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