SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e952b675f6d139920ce0aab6dda9c2658e7b4f77d1654323fcd942e25fd0382' 
  AND token = 'lW0YcJ3nBOQrT13mzm/sVA+EjfsYnJ2vtcbNzCYxm+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}