SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9a9217c983761d9df02c5ad59de952a615dd3149dcddd2e30700d56e8571371' 
  AND token = '0NKZyvqlhYWDDUZUBrV8Ve/cl2O4zd0CVuAKBH/ibqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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