SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d52d1b3d434a3ec79a6ca451750a20cb1006464f7a9ededa2e8b223e7587d42' 
  AND token = 'zGV1VOvK+9QPLrKH9EYX/XzOTtgK+G8uuhGSz0qB69g=' 
  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"
    }
  }
}