SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67b2ea342a2a694d5134e9212fcecf7e4a0e54909b4ce83bdd8fa78a435d4a5c' 
  AND token = 'h3w8IaOpbGgkLNjlDvyOIYbulVbAgqz2rZWl4rgudos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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