SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7bb6cc2a9b8f3f10079c74778d3176063de8051fabaef3d13296c6e5071871f' 
  AND token = 'KG/4p6JGtbl1z1hxnA4YqZJaDU8Q+S3+pw7CSQUMVfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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