SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70ea2c9d342397b27a0c2db9a41c80e8d75de55b6f8860341f9b0cc123f3e078' 
  AND token = '8nhlcy6whW8WcBIA9nu//nJfprsuCsTOx+bGa0AP8Ks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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