SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5697078d6a58157e7c2767775a1c77eb2f7b16749028bf0165ca14cdda1ff93f' 
  AND token = 'ONjJnCsOA2hUmC2hSXeYOiLWr/cnBdmZV6WOpNuwJZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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