SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85d7359b060cb88e88b0fbecfe65bb0f965973409359b928811b7a7cd43e74da' 
  AND token = 'rKLS7167N1mZYT6Zl35beBJEFafPIKbaLECgueHUMVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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