SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c2d178e5c73bf9c12fea0d604ee11828cbbf5c10cea1919c9eb308698b76454' 
  AND token = '41xGI9qJHZBQgR/w0ClxvPk2qFc7rlPebYFCnodqZS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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