SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3aa39eed8dd9420c94b49c656d81c0e059ec50e450e04e60bdcad398ee2b0ee9' 
  AND token = 'hG4mPir1ks07SH+3KB3Ucp63F55g8JqmN9AlSJF9uW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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