SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb19da7193bd3c9e5dea545ada9f229962135c0883bd3645491b22296351714d' 
  AND token = 'Qwdu4vvl/BUtj7YpzinuOs61i/SARkNQx8NVOgJU5s4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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