SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2135577b5acfe09af498847b6f1f6a6ef95063a71da6400f9cea20c4f40ec7e2' 
  AND token = 'v7+6TEJxsNZIrOokLwCQVedmlJYB7YgthR6ijwMZFdc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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