SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d4d7f45ed335dee19d6ca9de703942c2c0dca8995adc87451a30f4329f1bd2e' 
  AND token = 'sfxK87FOUR982uDUp6SboIyAgEkIkQk1yeobVwyMYeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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