SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed9375f508c54214f9d277ddd638fa8b449113d21bfd68aae002966134a56521' 
  AND token = 'caUqWI/OE9Y85BFGPs2sq01egEjZ2Qv+qh1KcC8IpgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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