SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dd2578e42a2ff360eeeee2888ffa61a8ae04ea241c189d4ef3376b0845c6fee3' 
  AND token = 'YmKLezu4V6s5+PHzqxxRx7/vJeLzOnkbqMfAOue9TfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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