SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3622b4a4633882cb2d785bfa92e4675348531e95a118130b45516cabc15cbe8' 
  AND token = 'wG89e8DZyhTDo2HJIkD3OX9CeREPXqb6IKDb5+jyg3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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