SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '685b221224b2c33d5f328a53085bec54646c1ee34d7e8867a674833cea5b633b' 
  AND token = 'qPqbX/BIuPEtgIt4XNOd+krYu+oPAsV2QSp1ln516Ng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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