SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e10a85659b91dc4ec686ce878524f932e9edba0366c39521fe6307f71af1d2b' 
  AND token = 'Pcz6NqInhpoi7c5+sqFK6v/+Q9oM3YJOROYg+OzMgjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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