SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ad5edf330a7cd14ae80dbcbf7c9c321118960e1acb1914e8228588694ecf57c' 
  AND token = 'yjb96g+hbisreF0a7OyrnxjjIjEQzQtfouJXuMoqE+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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