SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd98d3b41f185be7aa018bc877478f1ce641b25f6341cf2707bc97a67818d4cb2' 
  AND token = 'E/KxapSZp2FXf/fkfZaKzOK6DxSKWTuoGtHwLlwzIcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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