SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1b927afd8531f9765255d3981d423fe260cd097b3ee60893657fecc8fe0a9646' 
  AND token = 'LnNesUc+XVHWUvYmJjqeZ4LBbWYnlqsDbqb073+U7wU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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