SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '086dd57f9656922cdca65892a280ba09459671c79f4fe5b3b96920d80223b11f' 
  AND token = 'fcurZxP6/mmdkPd0OIzTAPh1r1bm4IxoXwWmRznRs8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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