SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdb583b9f0d57bf99a46a31cd990cba1060e31397e5db1c48b90a56b552d5a7f' 
  AND token = 'PE0CPubUJcIprw2WqFnm+AYZWKZsojYKXQ66wMv1Rro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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