SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49c2f4d27be9a4c19b8e3d70e92a0bce566b7aa017e8ef3ffbd62535812887c5' 
  AND token = 'xXVlUG38qxIqh6RDO3KtK41DGCw7HFE5JLuyzIWsmkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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