SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb48bc20c7d620f44a712a778e76a3a25e4e689ad71a93dbcff86455959c35bc' 
  AND token = '4y7OYlLx/SO/wbHdNJlhNVBRXgu95vI53h8GgvZtjw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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