SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4694240575e50756e5f7ef00097760f7273aaf924573b6757df193dccadf38b8' 
  AND token = '/D0PgyaJVDpBxe/xS0nImlFFSvmGjhSItKCgvwz5K7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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