SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9ec3bc18da444fded5788f355ab691f130009ab64ca003edab7ee0afb3481f5' 
  AND token = 'AFxHQwNio/gW2mgeShHqxKCEBFP1+cQiveiNk82nteQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 1.12376

JSON explain

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