SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '564ae228122820f2952e67e18f785dcfa8b49a40bb6be9cf66f74061667b146c' 
  AND token = 'I9jmchVDZxg/+0va9eKyrIJ0AWuY09QuT3z/gc44izU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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