SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83ec91fac695482416463028617be7655bd3861c830adcdbd6a8001cdf1863a6' 
  AND token = 'vEAsr4UtUksamyMpAIM/ln5GHfCVfxlGb2kk7MxJ7ak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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