SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '459994d9341c3e130fcb3fc4acb23bec67b761a12f1cade76239e346739685a5' 
  AND token = 'PmbLxQJKyoGq+9SowoM1M1B3G2D/bDX/WMFqHAh+YO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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