SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6c7ba387eab81db199d3feb43b22c399af3cb808420088b9d6bef9906187a002' 
  AND token = 'xXOD5V60JAMLIZEfx3/46lVhvo4DQa3uTRUG0asyEWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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