SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5eb474a8ec30a31eff14cf5714e97c9e0b782ab8d7990370f65dbc6758576c5' 
  AND token = 'pXqLWE26RcGmOeJBITM3rbl+8lTKelwHUoPibbVYaI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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