SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11bdd972bd08d00f0b2bdf2528370deefac096600e7f1561062d69dceced01d6' 
  AND token = 'JGcx/2OuyCdSefwNu88WxXkPKzGl2HD6SE0MKgecEWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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