SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38fc1caa8abe0304a362f4791f04593df859f7b3b4ff62373e3b493b31a7e184' 
  AND token = 'B0NeU/5YAZgKHltO2JUWdBjza879pxNsqGCdxW/0ffU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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