SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '575f4c07d007be99f31c8e5366fe33f07af488769b15e6ee58d9d9df4bef3115' 
  AND token = 'Fad9KZKazrYIJndw+CuhDpo6uNXlSv+H+7BSvyECUhs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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