SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7c4962e68d327438af87ef6de02817fb9517cb99d58091e027118706bebf444b' 
  AND token = 'UkQ3VPsMHL7jbTZaFVk8TNPrDArRCwzUZd1ugSKCagI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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