SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '72e8e0ad21576b9dfeaa10755f68358a92d128d175953cce9d447d815af04904' 
  AND token = 'vdabQo9YKhCBEQSXCnXmQ+swIeudCy04VuuggVwlbXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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