SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b7154632147778ce651f0cf3f33f626578d7ebbd11d0c4225b6775f194e6a5d' 
  AND token = 'tdIUoSpmwM7/M9xW99eJzKheUbDBoU1RQzxQBALo/1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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