SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '677b58d9328dea6ff1906c8d0e9b954923ecfcd7400cb9bf17544fe8b9d67664' 
  AND token = 'HrU6A5AkF50V95HhXPokovPGUUEa/wHoVcP3rESUs2A=' 
  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"
    }
  }
}