Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7293909911bd284245502ea712312bc62003512476e7c6ccfe88498cedf9f39' 
  AND token = 'UE91SDQbbiC89YgDI2bK1KopvMEZUqBuygJO7MYGT9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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