SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be9be1b944157a1a8e6a1abbce660c7bd92b81065560e8621fa292c6ffc95dee' 
  AND token = 'fSiagjTciadgKPV5GVdiM5VF16HQzLQPT66hkL4iVgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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