SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e825e692023891fc8d1fcdeb775f80c511969cc41410a1fbbcd04263626569bc' 
  AND token = 'NPWwcJwkZryvMWZH1hl+jhDy5PxfmpipGdLndRqoQS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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