SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '728c958f5766b7da947466d12f686620d51b84e28301c9d9e5b354b03b069a64' 
  AND token = 'Tka1Tp8olphlsgUZHLwxobvfWwI0/avzwkifqAZsTs0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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