SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '911c77c933724690825d43992b8d1190967f8cb0acb1458007ab5382fde2a44c' 
  AND token = '6pJZR3pq9Pyc2H2WPIoMepNxlH1Qceew1tywNPLXC8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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