SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a2f7ba4d9f6fa7f3cc9a4d7ce09134025dbb10aebd06e4712c1b0bac920a7e87' 
  AND token = 'BmSgquROO75O+ok37bjpOlDQ9pVrsELTt+4uR0vGVME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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