Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3d6d1711cd7ca9331c77193ff92364326d163340493fbda2aa683b780c5c857' 
  AND token = 'M4z31CKsATyh7QSX3rz0pQiCOndhqHiFzAILH2D89uw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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