SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7d94f89858d0c422bd04615349fd594d6316145701ee737fd3e095e1b2f4f23c' 
  AND token = 'th3U7HXo8aJ2o0FEzRhQPy7KGaQseUQRm/MPAsSYjrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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