SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '950b3188c095c1e3a89783ec1b7e2f54cecf1f879521fab4b4a6085609614dee' 
  AND token = 'BroygJ1Uk9JMOAHKDqPkRWm6AU8dJrvggAlwdI/eepA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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