SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0620523fe0d67afdf64c8fbeea32cc10aabc4da1b8fde6dc526aa87db7c184eb' 
  AND token = 'd5JrIgXNcsXIfYKqCWUf+lOBSESFjhnwKafaKMVjAt0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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