SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a67dd91291f374f2a5caecc15c0f2039a7ec9bc8a85cca9269573d00c5392ae2' 
  AND token = 'pGtA0KtHsG98V0ihBLKqPjVGi6wgJI43nu9k5YVzsqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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