SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '29d53acc54255e35cc21cd23e6c748e27e9fb9459d3fd13c548c078622328a70' 
  AND token = 'waU2xZC1UNycJpObWTUvS9ML1ZQWp+77CvssDkFMi84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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