SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e113eb88dfcc041d39ed0207da2dbe686b81f9de98679991cb290e8264e3622' 
  AND token = 'WFgyWOQmTD+cY7tDf04tRgliS0K/P0mEDqazdYcImEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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