SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bde38e35bf37a9a1f9ebaae13d64cc9648c81730dc845b79b3d8ec31d25f546' 
  AND token = 'lXal1vG1WIWmmCs/7JEh+MIMI11AtgR28/VYEhLOwYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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