SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '07a3449692665088b617803e12749daebff2edc2a400cab1a7c08f149d50db06' 
  AND token = '3DVjjclh/yZ34sHvWb0fcrOhFYOc61iGx1dkLFf+9GM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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