SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06df4d9e428a50bf0eb331979d9183c36f98c781649a9a40ff3b3cb8a5bcc797' 
  AND token = 'WkJQ91Q6+XSbRwbi0i3vY5ozluGejnT/cnqUuvBwlIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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