SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c37ffaba45e671fbe573a95fd7f82a14a302e7a4a8f510d621bc8bc40ef1ddb' 
  AND token = 'J6tDjcuNhvqD4XL2h38L7BBPOyKGhTGvZ5ic8+cvuTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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