SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b7d25ae2dd4d62afc8fce06aec13f479f95625149dc03942979d002b7934c55' 
  AND token = 'ml33neOVc8/EvOLlPmdW1crmyNrYtfFKEbG7buMFgzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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