SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01d0052973ab270ae129840d8945e00feb9ef8c273994d36e27729d35945736c' 
  AND token = 'etwScT2KZd0YsMKqR5NaxDfBcSzh15RYHbFnffLV9Ds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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