SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57d22ac7360d630e014ce330b90b07eb8df640687fd872afc9cdffe35c2beaed' 
  AND token = 'g7GjZt5efoQZU2jMK/3Yka4ozdDRtheoNDDpHfghDdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

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