SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72e26ae0de634c45a6ab64f9b36902836bf392e59aeff61a79de31987444aa21' 
  AND token = 'RIMFu/nPzj0pzwh4CBtHOqgJ8Mu3DbGvn92x7bgLWpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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