SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2b4581a6de7169f9e176d8a9e2e968d195f5f71a530d031fbf9e9e68f84f67c9' 
  AND token = 'iQU0Rrs7xqcJ6wFZcLEycurEIG+xNYZ2Vhduha+jmXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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