SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89d1148f67734bcbff1ed07a199913e7e1ed21d33cf2279afde65ca12249c543' 
  AND token = 'wmqDIb1SKA9tg6mrd2YEBFBBWlGnCzKSRarfWYdxaLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}