SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92c84bba241534d4f3d1a814ffe71570a0e6865f6f98cf6fd52abe5856f93d93' 
  AND token = 'VfaGcwyI/PPoccaixZmZixRNaSjijlGRgjUElOiVlVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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