SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f702b035666ebd4b4b83db16a0948f5012e733bb955d47c097b654c1c24ed919' 
  AND token = 'mEzcpPvF/K+OnmiQ0h5c0IKkUqpjXXaj2IWRMY8W5Gs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}