SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99b7228fbc74564cb00c653ebca2386101445e688ec4a5797cca913bd2870988' 
  AND token = 'ZAhAEKG47n0+k3IbmgkDd5mBZM5DR8RBbsDZpRE3UV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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