SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2317908493c0d2aa629eb7fc16ba4b0573a10edf2acbc398636a5f26bb935a6a' 
  AND token = 'ln3Uqrm0rzhTiOllRP8LNd0dwCoYIyR4VFJsYD6Ggj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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