SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3d1708f34412bfd24c30e42e0a312e04cc27420a3723f0f8c57c38d74e6d54e' 
  AND token = 'BB48cVKel/lBD8QB8LR1W7+A5I/6J5D3X4m9uRrYREc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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