SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ded3e34d8bb54c28f645d3bdb4c4b700a017a12e78b18ac0ac79e5aba77404c7' 
  AND token = 'ZBm6adl9MAHs0YP6s6f2KNwN1NsR9G0mchJHred9PTM=' 
  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"
    }
  }
}