SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dba956b771d64c7b6106e9b261ff0517cc00fd1b20866b2d83c7d7be27af8bf' 
  AND token = 'MJ+IJgXxD1h+YyJA4Ua6YD8WqypK6lD9ihVkSvcSkGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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