SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '221ced5c00f6804e75373771e96f6dec8b660a785e2f276691c093fc4710637f' 
  AND token = 'hfhYI2ZunliiwE+RoZGDkuGplMHgOjr4k4FOSFanZEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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