SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a92844f904958b1646771dd5e49101f8955554254b36ea47af61890378c842c' 
  AND token = 'vqRgsqJFgiJvcZ/TeT8yJ9FOM8kSH0sQlM9HHW81/hA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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