SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c895870157d3a28c229cd808a8684effb5ab8da6acbc980f6fe8559dc831b9f' 
  AND token = '8BmJjw5kNOsdVy1Fij8iUVA9lUsLGP/eAjODr3DbSKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}