SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59c26e2c729bb2b6e7a42ffa80657a3231e99ca0d210f3995b45d429e5ecf9bf' 
  AND token = '2t8AS7P5Rp++wyP/87Yuuyf/kb1ISJEWKaY7oKGNilI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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