SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85207d66f63f5d578be83739c61665ae66ced718f8abc0d79fa110420508ed81' 
  AND token = 'zto77Zg/lNyggFW+F8I/fxlX2tIaUaQhHyUQEz08244=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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