SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63f8ca7c2624c585925ed56f31a1440bac60a3bb4a30d8efa5c8d6bdb2acca70' 
  AND token = 'WQn9c4gMaCUUYq201C1JZ2NXRPEVDjqZLMbwEpK2cn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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