SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc5da9d70b92fc3b2551f6a07abe6818ef49a397f61373168ed8cb54b5ebc4f4' 
  AND token = 'FbclVODlSmljchMCf7RJuIZhJtHhdYwNwX7LYsJrUiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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