SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b071e199f5c909241db07907ccb4a585e053653367b125ef64f0c0a28383a21' 
  AND token = 'BDeFsy9VsHGEERCoK6doe1HSuavYxJlGZjQJZM4OjLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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