SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '799264dc8f6aaa1f16a496083cc25a338fac27da2e004dbd90b3fc09252ab232' 
  AND token = 'aB+LXxhlDS23xbnaSCgaffYjgIpwe9VO4wrSdkNoFHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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