SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '949dd27634251b8b49f8309ffd5060d2f57345d5c69f0ba146a615f8cd6e2ed4' 
  AND token = 'PR04HcCfdykInlu+kzRvKo3TYK4J87dojx51KBTsfnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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