SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b2d9c45b8dcf394c1141e27734a38ddeac847453873059e238ed39c6dbadf0d' 
  AND token = 'vdfCzL35Mym/JZIPnWzUvlJJ7NwwEsbJEQuAifneU1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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