SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2cb26ed92dd84afc9402c9ff00d62cadb27a35c1b5d2fb9c9ffc200d643ab3c9' 
  AND token = 'O5sJMIiHA1C0gCBmAJxK75SOxFX44o8Mmm3Afw1Lebs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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