SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f377ed00da28a5204a2478a0a6e2e402ba473e1f0ee8dd3b7894444df08dcd3' 
  AND token = 'Vacl4hRaAG998Uzq3w1H4DHNLQiD18Ap75omhRXLkDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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