SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a2498be637e48750006016c68849369b47b28cdafae7b70c001f4338d025341' 
  AND token = 'bdnpgyKxOZdIq0fxmg8iKJmkxYFTLbWZsaa9aG9hOoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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