SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '935ed64d84e3e02c2b030749a1d396453352433a41047d9635cd4438712cb42e' 
  AND token = 'D6qWBU434tVgSBDuZGTbdRkH40tkA/oWmG4EACaCff0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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