SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9f65c249ccc935ac1fb2821ac25b94a6249c6c2011965845008475066967256' 
  AND token = 'm9+zfqG6Jssb1ZXuFrSwuxejzb7mxDf57gXdTwmq9JQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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