SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '399551377576b9007b980a383a9bb816cac0e8b79ead53424d934dbbcd7932bc' 
  AND token = 'D1LXUQudvjJ0+nUYYfWo8YH1gqlW+BGBX1Wgf5d+h+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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