SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a30a4f929eb51caf39fab114b8a74845d737bb53f3f477c3b3ac6916853b37d1' 
  AND token = 'Sdk9hiCXlLrdHFv0yQGwUY5XQDg+8JSJqqJc7pDwU9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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