SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ffd1ee80f617652fe0ae49c6ed1ae8bad75a1e84d9fdba717b06e21096c71255' 
  AND token = '0nxWkj/FGqO8aFc225lA5cnNg66xsPmqcUBT1xuELgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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