SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9af519cbef08af17eb0c0dc4a4512d5fd190fc100ac3f49127841b55def338f' 
  AND token = 'oA6uoIvMKAzQ3ZoCCCxNkgBCJ5FQV53zk3Wr64WOb94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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