SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '237ad8a14c392678992daff3d38ea110c57e16035bf7a4b59c5dd088ec90b0a2' 
  AND token = 'kd2LNonGgbkrzcaQRAy3+dvZmB+YjMF4fWmgetheQsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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