SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e6eabf1bae258ca82854697bb4d847cf61cc33b8d96467247bd9e4244eb528a' 
  AND token = 'tVj718ajzZyk9US5aalry6aGd+ps4Dj5BVk3TRWwWLQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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