SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f46991476e036cda22b7f8ed35f6bf4aa4053a8c8b7b1a04c0897df0f4f2e9e' 
  AND token = 'hRjgtLwUiIeucMB17wjoKlAmXhLskZW2qxwjPmm8CK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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