SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fc4f7d4114715597ec70b865513c1d52d92a0cd5d959db3b02fddae9f72de6c' 
  AND token = 'KEEYp4avdwWqatEyhDOZuspDCal1o6Otc4FGITgmnZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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