SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ac1e23b573f3588706b311d923ddb9802d8f6ca3ef7dca7e0ab43f60769f9b43' 
  AND token = 'XqZ7vZz4/Qe3G6AC7Msb7TYyPR+tON8XPeh8Kz9Bjrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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