SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bea5a03d1117f942051f955103cd4ce7a7e6904acb31d5562e717837281caa4f' 
  AND token = 'y4btVxtLT0odZfGtN+1040PVxRv/zC41UhPiHfpnMv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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