SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '732cba167f4747613e34a61d99404b7aad0483204f9b93690f4d3307f95f1eb8' 
  AND token = 'RQC2Wm1FAtECLKRtLqRub5BDOcl5WTVIFbU7aUtZPDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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