SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af02b75658fbdee0d3504b604000c0040910fdad2e9fa59dfc01df88f97054fb' 
  AND token = 'mAKK+i9Yc/wks9us3SFxnubThRnKQHV/avDxshLPIvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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