SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd98d2936dcb3b6b8ec58bbd4527d043c1c5f8f477d2ccdf0265f9b5fd6addc3f' 
  AND token = 'vfa/AkzbqFg9j4EuoWlALqSvTcDvQGfpYP4/00H5UNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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