SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a113e52841693527b2c4ada43d5dff362b5b955cf844cac1a93743a5cdadb247' 
  AND token = 'buvivgJi+XqnlBfPBQZmM+vJW8TGNBNiSHGvb/vqa0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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