SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '433ae7a6519b12d179847c3dce8ebda836031dc5c521251d8dbb774839a1a4f7' 
  AND token = 'HOPFxPLeFnPQqvkTEZJr8OwKV0HUStPba0+LVq+Mij8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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