SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef71cb76c7e7a070ae9060ac3c930b89c325c634cd3712f644a41102b6feeb67' 
  AND token = 'fwKoZRci1BmzKjaTuXuDlPVUNh99IX2kqYl7akxxfqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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