SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdd88d2f9f222692d35af3cc214377e22901dcb14bc4ff07286f77dd1914dbba' 
  AND token = 'dxx/ZsNP6MSpKniB+5clKUEYUn8vxH2vPwhqY466vwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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