SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4c006f5a86c9f5c8b2aec678ce2bf1b75e183b9e39585f15b020fe5cc2210c52' 
  AND token = 'uRjd6Z9dT/uYf7fC1XaUpN1KzQ8Kkkc1D+UcsTTAHqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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