SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cc9de04b7931b76b3cfdcf7542970bf30ca232fc802d79bee24521f0eace8ff' 
  AND token = 'UiKWCEXgHPGG8i9Y9IvIQot88pD7i4qyVu9UMFvxcBE=' 
  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"
    }
  }
}