Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '23f76cfc03ab9473bac762e1771068df2bc9f705626cc909067c7ef59555a06e' 
  AND token = 'HBZvdb4oyj/4X1l7bmmmE80j/gusaJn8GSDQNffn/Lw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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