SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5a0a7ab54cdee2bc9572625b9c9714a84cc1d049c8de267bf5d183137d48de87' 
  AND token = 'lwivsQqSpQUvLu35FZt0jm58GvPGGQB8FeW0CfWEF1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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