SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83170fd87f9bcba62f0a10bf7475a38b477a39525d0337ef7ebf31f42d3d706d' 
  AND token = 'Qum9iyjzeub+scHfdLs3dxYXYgFkwKFtmemlAjkwO74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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