SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7692826b20274b5c821d34ba45bc846fc99c19ccb0e173c9ab9ca070abc3aafe' 
  AND token = 'JQkIYoME2PVKi1KpRYyPVbnWjDZqxWtaA6hoNLEM01M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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