SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00c4fe2f7cb0df23eb27879b373ffa57ad74be20acb0b5f9d6ffd6e67168d3ea' 
  AND token = 'lPWhqWFDzs+rUoTHdxjRjt6veatjdMMvyDb3lWvKx9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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