SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a863548e665f6d80743acb846cbed04430e628d9d7c9b62a150d514f8a566723' 
  AND token = 'yNlcPG/Tt9CsWMMnqSRMZha3vuYaIbKkIwkGvDcdR1k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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