SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '829bd758b30332f80e7214db67c50d1473e248bd28fe6747f237fbb920ed7530' 
  AND token = 'mn0GhQZiWCdpZOfPBmOgcWhMVu2zD5x4oaruCG27qoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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