SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3625b097331ed29630da8ad8f1a1a4850bff57d19d72fd75c861563b8c1d09ad' 
  AND token = 'wYTjqy6IARzuBqDzMHj7uy1vopAaOyH8KeApk5rYLsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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