SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c9641cd0a39ba971c9703db9c65c2fd0a3f3c29c48fce6a33addb0a48e1acde' 
  AND token = 'lijGfWV20vWpiSxaKKPYCVzQQy7qJHln23gVfh8PK+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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