SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7816bd06fe37093ac538186bb5979f254707f3a876e3ff9ced636fed2e16a1fd' 
  AND token = 'egF1SK8yBypjxca+aLzwxgnXSKqlAyrXuGJ1LVltP+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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