SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb974fa6bf63e04945df1613c3be36a180d082d6e83a93d70c12f68aca88dcd3' 
  AND token = 'WfQfqZgsYh9zBmj54tJxQQFTkaE54tl8/pp/k2sZX2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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