SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bd95d1bfab242e6554e59be358ef94ce489462da8dab4cd0762c66ccbdf9386' 
  AND token = 'oBYraySdIjV5xVV/1JHYENtYZ4nbLItHq3/X1wj/4N8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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