SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'eeff7edbef207a498ed4d6ec4051ebd1e81c8c422a1169764e8ddf0390185f75' 
  AND token = '9A6OcPE0/ULwwdmZgEZoKgJiRTvf+fXFOR2hGWmFvSQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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