SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '796a12d8122edfc40485313fbaa65bb339416e12dc23110ebd4130c1c28a4443' 
  AND token = 'vz5yE2VwuU5OtJMRdQGmV4mOW+l7BPnUWOXrhPokaRc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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