SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c640c0dc7f302596554445aa40e7ae35b7aaf46bbac59e4e9e9b0c4e189ac0ab' 
  AND token = 'AFENkUJol01xwearldgJXzGKj54NRp8CzmsEFSVtUa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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