SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d41430de52022dabf90852926486d4a684bbc4f0e42b16aaa2cd192ec22a311' 
  AND token = 'H/eIpcWCgzCjwjCh2i3zpbW8PdEXNKOyWHt7mJ5/eSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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