SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9825ca84ba41e5dfec7236d3b08e09b773161299205f256c4015c4ab9df116f' 
  AND token = 'dDMw/mHl24Ya3k3/Qqqa/KqBJIuQNl85qOaT6E1PL3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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