SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf8f9fd2ede6e83c9196cf76d30f24a3a08563c1e8fa4249b20c24dbb473acc4' 
  AND token = 'JMKn8+C2Kze+p17hp1p+I3eMHrL/d9lyQVB4BYPUOZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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