SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a06d6a2e95d207519812a5e4bdbcb2553bd53a83a510456b66da4ce3d92f8eef' 
  AND token = 'AJVqoVjaOeSg6Y2nYHrVWYywarZAEYYwZtvO4NlMHFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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