SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72550483b4b6bd644e797fc28618e333bee1f3931fcd6f1a4b2c21a9549f7250' 
  AND token = 'hd7aLNs2Vfyw24y5d1Q+irUZssDz/j08SLEHjK8I3lU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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