SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67204942431ddd00371cf81296503ac0bb92cd08b9864e48e4e1864271d2cb26' 
  AND token = 'OagXBE5uxyzW003uH8k00n2Qvk0+EtWmUJMpkPSwS1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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