SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2043279228d2e45033246b98d976f68447987dce4060fdc6fd7fbb10f5f659a0' 
  AND token = 'Av4pJXQGCqhWAB/J7BAaSg1Snfq2y7T7VkYTjff4j5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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