SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8216bfd2d7f28d5100f9ad7bebad7c740b7f5a606a6da96312de3f850f40062' 
  AND token = '/xE6lg9iANQXkYyM1S/zcFGWuOQZSi3WW869Dl2mc5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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