SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39424b9579ab4f26da476f44fc96d1ec1a52eef07e69cbb3fd3188fba90fdde6' 
  AND token = 's2vZqkPuyBPXEWSD3qexUpM2ZV5CuUMx7+GLZ8edUXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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