SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9de0b053810864adaf7e91bb5a58909f17cb630872babff83804e6905c4a77e' 
  AND token = 'dguRtu0mOwLW2esuPs8qKDlS3uzZoZIDlhrjhFghxkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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