SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16553b0a865e7011c90dc2cfb94afdf00db3524617caf878ef9b6c897cdf5b44' 
  AND token = 'wSeeSi0mynyQoV80zCCVVMCtmIcqxkOLqSCg+c6LaNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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