SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '123b97f85da8ffd0449cd69e5c73214d018f605ee4d42590f9a8254987f13629' 
  AND token = 'r+LnW7FwVvrtYxkrJpKYuCTxY7l7CWEF5YggoZOn33Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}