SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6f23c5ffa62b29b5abe511572be7c378ba426d7e34461af96ee5be3126e965b' 
  AND token = 'L1V+Zf8/7MMbemyn/cCgpnJYQlOyAeO7x7V+57Slbv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}