SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4d115008c1aee690ebeecdd00f4012b6afe350f648d84f7702655b1f8e64178' 
  AND token = 'oyYYti7drVgxszxhKTp5uxlx8PoozgfoSzxBSt3Eiug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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