SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d6d4182f171bb642205a4077293568f6bffb58867fce253898f8789767e4914' 
  AND token = '6YdKcRr8Jzyjg3sDyxKU1+Bd446iPCIGyRME+TlZsSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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