SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f439dceb253b9938362bfb1dfc95518053f047f0d47bdefa9366608896b169de' 
  AND token = 'KBGxcYGOD0SvG9vdYfHhufID9lyqmPFgyJxvCcOL5dA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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