SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b5eb5e009dc97b67afea3eb935f1540f0c785c1ff3f42f235a95f0a38a197d9' 
  AND token = 'wjxuDYZnE/QPZ1KgG4qtZhaIlvAUhIC7EivO16emB5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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