SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '083dcb44ab35bd9023a59f9c5d91003467c1fa641856b5dc313ec296bf603952' 
  AND token = 'zfixjCJBaocAQrJKwg4QWxoHb8sHwLfb8qWPqb0CVXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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