SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '800ba97870e680a2ed468091dfff29b433ba2ac488691ede560a8310643a6861' 
  AND token = 'BQn8X7iUJzVQPe552X3G8dYMFCQ0q8wu8pcCWR3NRr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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