SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f76b2e89a5bff9d70069c1088192b9ebee992c0fc70956e99352fea12169e8d' 
  AND token = 'Rli4Z9nfKqPVsdwioZ1HBI1BSPjru+Dauj9T/w6+MLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}