SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eab8c09b1c1266d2833374b83b984941e8a381fc0836bc46df591fcf1ced6473' 
  AND token = 'WEntpKWfsTKta5uikbbOnWdKQECCyuy0BkdExZvYlI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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