SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8d4cce507f0304d18dee4479a26342a35142262233af0cac3c60e1a767426cbb' 
  AND token = 'T2mmnw+oLKFNEkiVgRqANcQegzBQFYY8zFOo289Vg9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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