SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '534a3ec8384517cfa3cb990829d1e0abc7f34a8ea9d516b35157d5980d95ad8f' 
  AND token = '8whfHMFJpuVLqEW2gTmLwE3TWa5jRex7jYN+GSARbkA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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