SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4c87925d46eb293b790f9f1d8c48fa14e95f956acae49b4d88fc8a751a76431c' 
  AND token = 'oiw30/TXGCjPY3sTIOKcVtXCqXucmubQzIMaYy4UnDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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