SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd87f7401685249cec71f58f9ac8fc289dcd78e670b76cef1568b8525b3fc6e7' 
  AND token = 'zijpxGHeGaDiGSwZQoUKTcFDcr9netINGfr/UcyQQLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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