SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb923e15730498c6a474d12cb00d8196fcc98bb80673da7f967b5e2f08538b11' 
  AND token = 'wOIAj2JG7Lisx40m00Srb7Wl6VB4KYUXLPtv+OczeJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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