SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ad3bd26678a328e9482e9203065df2746d0f0558e19f98cac87713935cedbb5c' 
  AND token = 'QbaqmdTPzBqqSzvcVvNVsvz1SSgZq0yUrWFw6xOWX+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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