SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e31b94aa38dbf6ca5859ec6ab758fe6d6468d1b55ac420be50d022610e1ab41' 
  AND token = 'dZjBw9sFu+CJc9SguMraqpA2K18mP6dKYzLXSPrfOZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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