SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '479bf755c860aafda7d2b97adcfd2ea37d90925ef36c6fb6f28632faa548caae' 
  AND token = 'VbPlJNfzhqcygRa1vX3ot09P1bW+XzQ1JR+fBp5dSeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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