SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6071f44cb57f1f60151e2cecffcd4a6572123cc87a718919a5523722658cf0fa' 
  AND token = 'r4tRf9D5za6ZFjXepNUDSIJCsEJ43sPftB8/FsyJpNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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