SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dffc70ce737bcbc9acd48850bc20fd9eba511fed5b4273d1ad50e0d71237a3d8' 
  AND token = 'LHCSXQM38dJei8naJhrVt6aAlE8eQjxGZxLyaMSHzFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00080

JSON explain

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