SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ebffa623710de7f411ca2ce2497eb5f6e52ec6676581aaa6e0b4ce472e3df53' 
  AND token = 'VsJeqXJTZHVCcMnbwdjT/o2QU5mi5dBjxvBtAZo6XUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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