SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3f0d81717040dcaa7c8b76005db06fa576512330c44d98f9318d9e2ee4f8283' 
  AND token = 'NsB3oi2WRJZN6CNKOlEk8MHBHcGHYhppBVIvwQpRmh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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