SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '472712e9a92c99543ec7b542b2bedf824c94bdfaa71c1e6bd62c42f35836a602' 
  AND token = 'KiFs7E7uFtZPWeCXoOFYDRtDeZ6T+CmvcK9ZcMceEZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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