SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '959414f84ec0a39c21293d5ae323e34b377968655d0be92bc848643c9bb45980' 
  AND token = '1ozT0/RbjgIv5d6rABUylQHqJ5Br7wmx+SRKKE0XCDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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