Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '849ddbba5b491c0c9019b82ef3468e1eaa235b4f92b9df9d848bc248c4fa3d9a' 
  AND token = 'LMumZbVIsKfC8L+mJId1TXcBiSc1E7e63Rs/rHmqGjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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