SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee7d6fdfa1d0ae1d4b32886e838404b53cdcb78b327b4d1d90d6ec9187024384' 
  AND token = 'Z36hzjiZ6FVGMYxf3WdBzsCfaoXlsKL2cglynwPvCT4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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