SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4eafaf20a3b83a37d920945af7be77b0118fee408e615dc71792b555e43467d1' 
  AND token = 'K5vn12700+MWjceh1h09DBF3XnrzlJBRqZVpEW/GFis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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