SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '717d226a85d9e9d815309fc7b632997e2310e4bf99c13705adcd84cc82a31ee5' 
  AND token = 'SC/U8b0RaCLlDE50naXczVrkivn4HM26TfhCg5XkQNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}