SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ee406544ec8ac864e65b08e50b847850a61473ec3022981ef1563f88172bb1f' 
  AND token = 'ZRNZJ/Qh7fvgPfGo36mTG2EgvHiwEWiBAGaNnyTJJGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}