SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80cb0961b7f81eaae07a70224b0281532f9b8fea735de12bb16a669a349134a0' 
  AND token = 'zvGqihblI7+mby6KBSP0FKCevLLME30/TxvM01hr8aY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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