SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63f592e30eb8048f5c2f3f24d5846da669fbba6807d6da48a6a72e9478f30ad4' 
  AND token = 'mT5rvEFESShpfSaxuIGJ6pNaISBpi2cE6ZE78ORo/Ps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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