SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3501d7d2f3d60fa7eb5a1eef3cdcebbde16af71add7d58a8be690f51c3844880' 
  AND token = 'Xu3iW+NBaOQClE0cQzq7CzaD75ItYltOD2eJ83d8aNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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